LockPush — Ballard Locks wait forecast

Ballard Locks, measured: wait times by hour, and after dark

Ballard Locks wait times — measured, not guessed

Last updated 2026-09-04. Two windows, and the page says which throughout (plus a third, 37 days to 4 September, used only for the weekday-weekend comparison and stated there). The headline figures and every hour-of-day median come from a closed 30-day window: 1,176 US Army Corps of Engineers lockage records for 30 July – 28 August 2026, of which 781 are recreational and 395 commercial. The distribution plates further down are computed separately over a longer archive — 1,304 records for 31 July – 2 September 2026, 837 recreational and 467 commercial — because a distribution wants every observation available and a published median wants a window that does not move under it. Where the two disagree slightly, that is why.

Every number on this page is computed from the Corps' own lockage log for the Hiram M. Chittenden Locks — arrival time, doors-closed time and cleared time for every lockage — not from anecdotes. The live forecast applies the same data to the current moment.

The short version: a recreational boat's median trip is 27 minutes. The hour you arrive moves that median by 24 minutes: a median 44 minutes at noon against 20 minutes at 8 pm. In the 781 recreational lockages measured, the fastest clear was 10 minutes.

What the numbers mean. Every figure on this page is transit time unless it says otherwise: arrival to clearing the chamber, including the roughly 18-minute lockage itself, not queue time alone. The queue — arrival to the doors closing, the part you actually spend waiting — has a median of 8 minutes, and the chamber cycle a median of 18 minutes. So a 27-minute median means about 8 minutes waiting and then 18 minutes locking through, not 27 minutes of sitting followed by a lockage.

Median transit time by hour of day

Shaded: the Ballard, Fremont and University bridges do not open for pleasure craft, weekdays 07:00–09:00 and 16:00–18:00 (33 CFR 117.1051; the full bridge schedule is on the transit guide).
Median transit — arrival to clear — for recreational vessels by hour of arrival, from the 781 recreational lockages recorded between 30 July and 28 August 2026. Every hour from 06:00 to 22:00 is shown. The best-and-worst daylight comparison quoted on this page covers 06:00–21:00; 22:00 falls outside it. Bars are drawn to the slowest hour (44 minutes at noon); ▲ marks the 11:00–14:00 peak; ▼ marks the hours at or under 22 minutes within that window — the 3 o’clock exception and the 18:00–21:00 evening band. 22:00 is the lowest figure on the table but sits outside the window, so it is unmarked.
Arriving atMedian arrival-to-clear
06:00
23 min
07:00
28 min
08:00
30 min
09:00
35 min
10:00
34 min
11:00
42 min
12:00
44 min
13:00
39 min
14:00
43 min
15:00
22 min
16:00
30 min
17:00
25 min
18:00
21 min
19:00
21 min
20:00
20 min
21:00
22 min
22:00
18 min

What the shading does and does not say. Those four rows are hours in which the Ship Canal bridges will not open for pleasure craft on a weekday. They are not hours in which the locks are slower, and the medians in them are not caused by the bridges — the rule affects only vessels that need an opening, which is sailboats with standing rigging, and the table pools weekdays with weekends, when the rule does not apply at all.

The row is also your lock arrival hour, and the bridges sit upstream of the locks. A boat arriving at the locks at 08:30 and heading for the lakes does not meet the Ballard Bridge until roughly half an hour later, by which time the morning window has closed; a boat leaving the lakes passes under it fifteen to twenty-five minutes before it reaches the locks. So read the shading as “plan the bridge separately”, not as “add this to your wait”.

The peak is late morning into early afternoon: 11:00 to 14:00 runs a median of 39–44 minutes, and noon is the slowest hour of the day at 44. Commercial traffic goes first by law and clusters in those hours, which is most of what that peak is made of. The 3 o'clock hour is the sharp exception — median 22 minutes, half of noon — though 16:00 goes back up to 30 before the evening settles in: 18:00 to 21:00 runs 20–22 minutes, as quick as 3 pm and four hours long instead of one. Worst to best across daylight is 24 minutes: 44 at noon against 20 at 20:00. The day also opens quick — 23 minutes at 06:00 — but has tightened to 28 by 07:00 and 35 by 09:00.

These are measured figures for the window stated, not a live reading. Current conditions, and how today is actually running, are on the live forecast. And one month of high summer is one month: this pattern is measured for 30 July – 28 August 2026 and is untested in other seasons.

The shape of a wait, and the shape of a lockage

The hourly medians above compress each hour to one number. These are the full distributions behind them, from 1,304 lockages over 34 days (31 July – 2 September 2026), in 5-minute bins, shaded by the hour the boat arrived. They answer a question a median cannot: how often does the typical case actually happen?

Recreational time waiting outside the chamber

Arrival to the start of the lockage — queue only, with the lockage itself excluded.

Early morning 05–09Middle of day 09–15Late afternoon 15–20Night 20–05
0751502253000–4 min · Early morning 05–09 · 50 of 2690–4 min · Middle of day 09–15 · 58 of 2690–4 min · Late afternoon 15–20 · 116 of 2690–4 min · Night 20–05 · 45 of 2695–9 min · Early morning 05–09 · 51 of 1875–9 min · Middle of day 09–15 · 60 of 1875–9 min · Late afternoon 15–20 · 56 of 1875–9 min · Night 20–05 · 20 of 18710–14 min · Early morning 05–09 · 23 of 9710–14 min · Middle of day 09–15 · 37 of 9710–14 min · Late afternoon 15–20 · 28 of 9710–14 min · Night 20–05 · 9 of 9715–19 min · Early morning 05–09 · 17 of 6615–19 min · Middle of day 09–15 · 24 of 6615–19 min · Late afternoon 15–20 · 17 of 6615–19 min · Night 20–05 · 8 of 6620–24 min · Early morning 05–09 · 19 of 5620–24 min · Middle of day 09–15 · 30 of 5620–24 min · Late afternoon 15–20 · 6 of 5620–24 min · Night 20–05 · 1 of 5625–29 min · Early morning 05–09 · 4 of 5225–29 min · Middle of day 09–15 · 33 of 5225–29 min · Late afternoon 15–20 · 13 of 5225–29 min · Night 20–05 · 2 of 5230–34 min · Early morning 05–09 · 2 of 4230–34 min · Middle of day 09–15 · 22 of 4230–34 min · Late afternoon 15–20 · 15 of 4230–34 min · Night 20–05 · 3 of 4235–39 min · Early morning 05–09 · 2 of 2135–39 min · Middle of day 09–15 · 14 of 2135–39 min · Late afternoon 15–20 · 5 of 2140–44 min · Early morning 05–09 · 1 of 1440–44 min · Middle of day 09–15 · 8 of 1440–44 min · Late afternoon 15–20 · 4 of 1440–44 min · Night 20–05 · 1 of 1445–49 min · Middle of day 09–15 · 3 of 745–49 min · Late afternoon 15–20 · 4 of 750–54 min · Middle of day 09–15 · 2 of 550–54 min · Late afternoon 15–20 · 2 of 550–54 min · Night 20–05 · 1 of 555–59 min · Middle of day 09–15 · 1 of 160–64 min · Early morning 05–09 · 2 of 760–64 min · Middle of day 09–15 · 3 of 760–64 min · Late afternoon 15–20 · 2 of 765–69 min · Middle of day 09–15 · 3 of 370–74 min · Early morning 05–09 · 1 of 370–74 min · Middle of day 09–15 · 2 of 375–79 min · Middle of day 09–15 · 2 of 280–84 min · Late afternoon 15–20 · 2 of 285–89 min · Middle of day 09–15 · 1 of 1110–114 min · Middle of day 09–15 · 1 of 1125–129 min · Middle of day 09–15 · 1 of 10153045607590105120135median 8p90 31MINUTES
n
837
25th
3 min
median
8 min
75th
20 min
90th
31 min
max
128 min

A decay curve, not a bell. The commonest outcome is almost no wait at all — 269 of 837 lockages began within five minutes of the boat arriving. But the tail is long: the mean is 13.5 against a median of 8, and the worst wait recorded was 128 minutes.

Chamber time, every vessel

Start of the lockage to clearing the chamber, recreational and commercial together.

Early morning 05–09Middle of day 09–15Late afternoon 15–20Night 20–05
01002003004000–4 min · Night 20–05 · 1 of 15–9 min · Early morning 05–09 · 6 of 215–9 min · Middle of day 09–15 · 2 of 215–9 min · Late afternoon 15–20 · 7 of 215–9 min · Night 20–05 · 6 of 2110–14 min · Early morning 05–09 · 69 of 27010–14 min · Middle of day 09–15 · 69 of 27010–14 min · Late afternoon 15–20 · 82 of 27010–14 min · Night 20–05 · 50 of 27015–19 min · Early morning 05–09 · 89 of 38615–19 min · Middle of day 09–15 · 154 of 38615–19 min · Late afternoon 15–20 · 101 of 38615–19 min · Night 20–05 · 42 of 38620–24 min · Early morning 05–09 · 45 of 29920–24 min · Middle of day 09–15 · 158 of 29920–24 min · Late afternoon 15–20 · 71 of 29920–24 min · Night 20–05 · 25 of 29925–29 min · Early morning 05–09 · 19 of 14225–29 min · Middle of day 09–15 · 69 of 14225–29 min · Late afternoon 15–20 · 45 of 14225–29 min · Night 20–05 · 9 of 14230–34 min · Early morning 05–09 · 8 of 6030–34 min · Middle of day 09–15 · 29 of 6030–34 min · Late afternoon 15–20 · 15 of 6030–34 min · Night 20–05 · 8 of 6035–39 min · Early morning 05–09 · 4 of 2735–39 min · Middle of day 09–15 · 10 of 2735–39 min · Late afternoon 15–20 · 7 of 2735–39 min · Night 20–05 · 6 of 2740–44 min · Early morning 05–09 · 1 of 2340–44 min · Middle of day 09–15 · 14 of 2340–44 min · Late afternoon 15–20 · 5 of 2340–44 min · Night 20–05 · 3 of 2345–49 min · Early morning 05–09 · 2 of 2445–49 min · Middle of day 09–15 · 17 of 2445–49 min · Late afternoon 15–20 · 4 of 2445–49 min · Night 20–05 · 1 of 2450–54 min · Early morning 05–09 · 2 of 1250–54 min · Middle of day 09–15 · 6 of 1250–54 min · Late afternoon 15–20 · 2 of 1250–54 min · Night 20–05 · 2 of 1255–59 min · Middle of day 09–15 · 6 of 755–59 min · Late afternoon 15–20 · 1 of 760–64 min · Middle of day 09–15 · 6 of 760–64 min · Late afternoon 15–20 · 1 of 765–69 min · Middle of day 09–15 · 1 of 565–69 min · Late afternoon 15–20 · 4 of 570–74 min · Middle of day 09–15 · 9 of 1070–74 min · Late afternoon 15–20 · 1 of 1075–79 min · Late afternoon 15–20 · 1 of 180–84 min · Middle of day 09–15 · 4 of 680–84 min · Late afternoon 15–20 · 2 of 685–89 min · Middle of day 09–15 · 2 of 295–99 min · Middle of day 09–15 · 1 of 10153045607590median 19p90 34MINUTES
n
1,304
25th
15 min
median
19 min
75th
25 min
90th
34 min
max
95 min

A proper peak, and a tight one: half of all lockages clear in 15–25 minutes. This is a physical process running at its own speed, and it barely moves with the clock — 17 minutes in the early morning against 21 at midday. The chamber is near-constant; almost all the variation a boater feels is queue. That is why the hour you arrive matters and the hour the gates close does not.

Commercial time waiting outside the chamber

The same measure as the first plate, commercial vessels only.

Early morning 05–09Middle of day 09–15Late afternoon 15–20Night 20–05
02550751000–4 min · Early morning 05–09 · 19 of 760–4 min · Middle of day 09–15 · 20 of 760–4 min · Late afternoon 15–20 · 19 of 760–4 min · Night 20–05 · 18 of 765–9 min · Early morning 05–09 · 21 of 835–9 min · Middle of day 09–15 · 41 of 835–9 min · Late afternoon 15–20 · 8 of 835–9 min · Night 20–05 · 13 of 8310–14 min · Early morning 05–09 · 16 of 8310–14 min · Middle of day 09–15 · 43 of 8310–14 min · Late afternoon 15–20 · 18 of 8310–14 min · Night 20–05 · 6 of 8315–19 min · Early morning 05–09 · 1 of 4115–19 min · Middle of day 09–15 · 30 of 4115–19 min · Late afternoon 15–20 · 3 of 4115–19 min · Night 20–05 · 7 of 4120–24 min · Early morning 05–09 · 4 of 4020–24 min · Middle of day 09–15 · 22 of 4020–24 min · Late afternoon 15–20 · 5 of 4020–24 min · Night 20–05 · 9 of 4025–29 min · Early morning 05–09 · 4 of 4525–29 min · Middle of day 09–15 · 30 of 4525–29 min · Late afternoon 15–20 · 9 of 4525–29 min · Night 20–05 · 2 of 4530–34 min · Early morning 05–09 · 2 of 2930–34 min · Middle of day 09–15 · 20 of 2930–34 min · Late afternoon 15–20 · 3 of 2930–34 min · Night 20–05 · 4 of 2935–39 min · Early morning 05–09 · 1 of 1335–39 min · Middle of day 09–15 · 10 of 1335–39 min · Night 20–05 · 2 of 1340–44 min · Middle of day 09–15 · 7 of 1040–44 min · Late afternoon 15–20 · 2 of 1040–44 min · Night 20–05 · 1 of 1045–49 min · Early morning 05–09 · 1 of 645–49 min · Middle of day 09–15 · 4 of 645–49 min · Late afternoon 15–20 · 1 of 650–54 min · Early morning 05–09 · 1 of 1350–54 min · Middle of day 09–15 · 7 of 1350–54 min · Late afternoon 15–20 · 4 of 1350–54 min · Night 20–05 · 1 of 1355–59 min · Middle of day 09–15 · 5 of 955–59 min · Late afternoon 15–20 · 4 of 965–69 min · Early morning 05–09 · 2 of 665–69 min · Middle of day 09–15 · 3 of 665–69 min · Late afternoon 15–20 · 1 of 675–79 min · Middle of day 09–15 · 2 of 375–79 min · Late afternoon 15–20 · 1 of 380–84 min · Middle of day 09–15 · 2 of 380–84 min · Late afternoon 15–20 · 1 of 395–99 min · Middle of day 09–15 · 1 of 1100–104 min · Middle of day 09–15 · 3 of 3105–109 min · Middle of day 09–15 · 1 of 1120–124 min · Early morning 05–09 · 1 of 1130–134 min · Middle of day 09–15 · 1 of 10153045607590105120135median 14p90 45MINUTES
n
467
25th
7 min
median
14 min
75th
27 min
90th
45 min
max
187 min

Commercial waits longer than recreational, not less — median 14 against 8. That is not a contradiction of its legal priority: commercial vessels do not share a lockage, so they wait for a chamber set up for them alone, while a pleasure boat can join a cycle already forming. Priority decides who goes first once a cycle runs; it does not conjure one out of turn.

Commercial chamber time

Commercial vessels only, to be read against the all-vessel chamber plate above.

Early morning 05–09Middle of day 09–15Late afternoon 15–20Night 20–05
038751121505–9 min · Early morning 05–09 · 1 of 55–9 min · Late afternoon 15–20 · 3 of 55–9 min · Night 20–05 · 1 of 510–14 min · Early morning 05–09 · 17 of 6110–14 min · Middle of day 09–15 · 29 of 6110–14 min · Late afternoon 15–20 · 11 of 6110–14 min · Night 20–05 · 4 of 6115–19 min · Early morning 05–09 · 23 of 11915–19 min · Middle of day 09–15 · 66 of 11915–19 min · Late afternoon 15–20 · 15 of 11915–19 min · Night 20–05 · 15 of 11920–24 min · Early morning 05–09 · 14 of 10520–24 min · Middle of day 09–15 · 59 of 10520–24 min · Late afternoon 15–20 · 13 of 10520–24 min · Night 20–05 · 19 of 10525–29 min · Early morning 05–09 · 10 of 5825–29 min · Middle of day 09–15 · 34 of 5825–29 min · Late afternoon 15–20 · 8 of 5825–29 min · Night 20–05 · 6 of 5830–34 min · Early morning 05–09 · 2 of 3430–34 min · Middle of day 09–15 · 18 of 3430–34 min · Late afternoon 15–20 · 6 of 3430–34 min · Night 20–05 · 8 of 3435–39 min · Early morning 05–09 · 3 of 1935–39 min · Middle of day 09–15 · 4 of 1935–39 min · Late afternoon 15–20 · 6 of 1935–39 min · Night 20–05 · 6 of 1940–44 min · Early morning 05–09 · 1 of 1440–44 min · Middle of day 09–15 · 7 of 1440–44 min · Late afternoon 15–20 · 4 of 1440–44 min · Night 20–05 · 2 of 1445–49 min · Early morning 05–09 · 1 of 1745–49 min · Middle of day 09–15 · 11 of 1745–49 min · Late afternoon 15–20 · 4 of 1745–49 min · Night 20–05 · 1 of 1750–54 min · Early morning 05–09 · 1 of 950–54 min · Middle of day 09–15 · 5 of 950–54 min · Late afternoon 15–20 · 2 of 950–54 min · Night 20–05 · 1 of 955–59 min · Middle of day 09–15 · 2 of 355–59 min · Late afternoon 15–20 · 1 of 360–64 min · Middle of day 09–15 · 5 of 660–64 min · Late afternoon 15–20 · 1 of 665–69 min · Late afternoon 15–20 · 3 of 370–74 min · Middle of day 09–15 · 7 of 780–84 min · Middle of day 09–15 · 4 of 680–84 min · Late afternoon 15–20 · 2 of 685–89 min · Middle of day 09–15 · 1 of 10153045607590median 21p90 46MINUTES
n
467
25th
16 min
median
21 min
75th
30 min
90th
46 min
max
85 min

Three minutes above recreational at the median (21 against 18) and eighteen above it at the 90th (46 against 28). The middle barely moves; the tail is where a large hull costs you, which is the signature of careful line work on a barge tow rather than a slow chamber.

Why the hour you arrive matters

Hour of day is the largest lever you can plan around in advance. Twenty-four minutes separate the best and worst daylight hours on a median trip, and the slow hours run roughly double the quick ones. That is a bigger effect than weekday versus weekend, bigger than direction of travel, and bigger than the size of your boat. Only cycle position — where in the chamber cycle you happen to arrive, below — moves a median trip more, and that is luck rather than planning. Hour of day is also the part of the locks that most boaters have backwards.

The reason is that this is not a queue in the ordinary sense. The chamber cycle is a fixed quantum — doors close, water moves, doors open — and you either make the cycle that is loading when you arrive or you wait out the whole of the next one. There is no partial credit. Two boats arriving a few minutes apart can clear a full cycle apart. So the hourly medians are not a smooth curve rising and falling with traffic; they track the share of arrivals in that hour that made their cycle, and that share moves sharply from one hour to the next.

What moves it is mostly commercial traffic. Tugs, barges, government vessels and the daily tour boats have legal priority, and a commercial movement generally takes the chamber to itself, so it costs every recreational boat behind it a full cycle. Those movements are not spread evenly through the day — they cluster, and across the same window the busiest daylight hour for commercial lockages carries 8.5 times the arrivals of the quietest. Recreational volume, by contrast, is close to flat: busiest daylight hour to quietest varies by only about 14% from hour to hour. The 24-minute swing in the table above is therefore not small boats getting in each other's way. It is commercial clustering plus cycle luck.

One correction worth making, because the obvious phrasing is wrong. Commercial traffic having priority does not mean it sails straight in. Measured over the longer archive, a commercial vessel's own median wait is 14 minutes against a recreational boat's 8 — it waits longer than you do. Both facts hold at once: commercial does not share a lockage, so it waits for a chamber set up for it alone, while a pleasure boat can join a cycle already forming. Priority settles who goes first once a cycle runs; it does not conjure one out of turn. What costs you is not that commercial is quick, but that its cycle is one you are not in.

The distributions below make the same point from the other side. Chamber time is nearly constant across the day — 17 minutes in the early morning against 21 at midday — while waiting swings roughly threefold, 7 / 14 / 5 / 5 minutes across morning, midday, afternoon and night. The lock is not slower at noon. The queue in front of it is longer.

That is why the intuitive rule — go when it looks quiet — picks the wrong hours: the times with the fewest small boats on the water are not the times with the shortest transits, and the busiest hours for recreational traffic are not the slowest ones. The 3 o'clock hour is the plainest example. It is not a quiet hour on the water, and at a median of 22 minutes it is among the quickest of the day.

Queue and chamber are different animals

The chamber cycle — doors close, water moves, doors open — is mechanical: median 18 minutes through the afternoon, falling to about 13 in the hours after sunset (measured on the after-dark page). It is the floor you cannot argue with, and it is the larger half of a median trip. The queue is the part that moves, and its median is 8 minutes — that is the median across all arrivals, not the figure for a good day.

What decides which side of that median you land on is mostly where in the cycle you turn up. Split the recreational lockages by how long before arrival your direction's doors last closed:

Median transit by cycle position, recreational lockages, 30 July – 28 August 2026.
Minutes since your direction's doors closedMedian transitn
0–1050 min41
10–2041 min112
20–3529 min218
35–6024 min232
60+23 min145

Worst to best is 2.08× — arriving just after the doors have shut roughly doubles the median trip against arriving late in a cycle. That is why LockPush shows ranges and probabilities rather than a single average: an average is a number almost nobody actually experiences.

Weekdays vs weekends

In summer, recreational volume is flat — 26.0 lockages/day on weekdays and 26.0 on weekends. Commercial traffic falls from 14.9 lockages/day to 8.5: the working tugs and government vessels run Monday–Friday, leaving the daily tour boats. (Those are the closed 30-day window's figures; over the 37 days to 4 September they read 24.7 against 25.5 recreational and 16.0 against 9.4 commercial — the same shape.) The forecast classes holiday Mondays with weekends; no federal holiday fell inside either window, so that is a rule, not a measurement.

Unadjusted, the median recreational transit is 26 minutes on weekdays and 29 at weekends (37 days to 4 September, 667 and 255 lockages; in daylight, 28 and 31). Adjusted for hour of arrival — weekend lockages reweighted to the weekday mix of daylight hours — the difference is +4 minutes at the median, 28 against 32 (90% interval 0 to +11 resampling whole days; n = 600 weekday, 221 weekend), and a regression with a term for every daylight hour and for direction agrees at +4.0 (0 to +9). The queue is the same on both (median 9 minutes at the same hour); the extra is chamber time — across the day, not hour-adjusted, a median of 20 minutes at weekends against 18 (6 am–9 pm; 21 against 18 in daylight), and 2 to 5 minutes longer in every 3-hour band. Commercial traffic cannot be what makes them slower, and the fits allow it at most about a third of the size: it is lower at weekends, and adding commercial counts to the regression moves the weekend term by about a minute either way (−1.3 to +0.4). By day, against the Monday–Friday average at the same hour: Sunday +8 to +10 minutes, Friday +4 to +8, Tuesday −4, Saturday 0 (interval about −3 to +7). With ten weekend days the intervals are wide: the pooled +4 touches zero on the median and crosses it on the mean, a best estimate rather than an established gap. The table by hour band, the per-day figures and the caveats are in the How-to's weekend section.

When it gets much worse

None of the figures above hold on event days or during chamber closures — Opening Day and the other event days; the large lock's maintenance closure of ~2–3 weeks most Novembers, when the small lock (vessels under ~120 × 26 ft) carries everything; and low-water summers, when the Corps has routed all traffic through the small lock to conserve water (July 2024), pushing transits well past an hour (the chambers are described on how the locks work).

Common questions

How long is the wait at the Ballard Locks right now?
LockPush's live forecast at lockpush.app is the only measured answer: it computes the current expected transit time — arrival to clearing the chamber — from the Corps' own lockage records, refreshed every 5 minutes, by direction. There is no official live figure.
How long does it take to go through the Ballard Locks?
About 27 minutes for a recreational boat. That is transit time: arrival to clearing the chamber, including the roughly 18-minute lockage itself, not queue time alone. Measured across 781 recreational lockages in 30 days (30 July – 28 August 2026). It splits into a median 8-minute queue — arrival to doors closing, and that 8 is the overall median, not the good case — plus the 18-minute chamber cycle. Half of boats clear in 20–42 minutes, and a commercial lockage in the 15 minutes before you arrive lifts the median transit to 42 minutes against 26 when there is none.
What is the best time of day to go through the Ballard Locks?
Evenings, and the 3 o'clock hour. Measured across 1,176 lockages — 781 recreational, 395 commercial — between 30 July and 28 August 2026, the median transit (arrival to clearing the chamber) runs 39–44 minutes from 11 am to 2 pm, drops to 22 minutes at 3 pm, and holds at 20–22 minutes from 6 pm to 9 pm. Worst to best across daylight is 24 minutes: noon 44 minutes against 8 pm 20 minutes. The evening band is as quick as 3 pm and lasts four hours instead of one. It does not track recreational traffic: small-boat arrivals are close to flat all day, arrivals varying by only about 14% from hour to hour, while commercial arrivals, which have legal priority and generally take the chamber alone, swing 8.5-fold. These are measured figures for one high-summer month, not a live reading, and the pattern is untested outside August. LockPush's live forecast gives the measured expectation for the current moment, by direction.
What is the fastest possible trip through the locks?
The fastest quarter of recreational boats clear in 20 minutes or less, and 10 minutes is the absolute floor: across 781 recreational lockages in 30 days, not one cleared in under 10 minutes. The 18-minute chamber cycle is most of any trip, so the shortest outcome worth planning for is the fastest quartile — 20 minutes of transit, arrival to clear.
Are weekends busier at the Ballard Locks?
For recreational boats in summer, barely: 26.0 lockages/day on weekdays against 26.0 on weekends. What changes is commercial traffic, which falls from 14.9 lockages/day on weekdays to 8.5 on weekends, because the working tug fleet runs Monday–Friday. Weekends are slightly slower all the same: at the same hour of daylight a weekend trip runs about 4 minutes longer at the median (32 against 28; a best estimate from ten weekend days whose 90% interval runs from 0 to about +10); the extra is chamber time, commercial traffic cannot be what makes them slower, and the fits allow it at most about a third of the size, and on the records it is a Sunday effect (Sunday +8 to +10 minutes at the same hour by two methods, 90% interval roughly +3 to +18; Saturday 0 with an interval of about −3 to +7) — the figures are in the How-to's weekend section.

The Ballard Locks after dark

Last updated 2026-08-29 · measured across 1,176 lockages over the 30 days from 30 July to 28 August 2026, from US Army Corps of Engineers records

The locks run all night. Twenty-four hours a day, year round, on demand, no timetable and no fee — attendants are on duty and VHF channel 13 is staffed through the night. A two in the morning lockage is routine.

The obvious question is whether it is worth waiting for. The answer is yes, but the reason is not the one most boaters give, and getting the reason right changes when you should actually leave.

Traffic collapses after sunset

A note on the numbers. Every figure on this site is transit time — from the moment you arrive off the guide piers to the moment you clear the chamber, the lockage itself included, not queue time alone — and the split between queue and chamber is measured on the wait-times page.

Recreational traffic runs remarkably flat through the day and then falls off a cliff. Indexed to sunset, which is the fair way to compare across a month in which sunset moved 51 minutes earlier:

Lockages per hour and median recreational transit time (arrival to clear), by time relative to sunset. 1,176 lockages, 30 July – 28 August 2026 (30 days).
Relative to sunsetCommercial /hr Recreational /hrMedian transit
6–4 hours before0.771.4028 min
4–2 hours before0.321.8725 min
2–0 hours before0.341.7820 min
0–2 hours after0.210.8523 min
2–5 hours after0.090.0918 min

Comparing the two hours before sunset with the two hours after, recreational traffic falls to 48% of its pre-sunset rate; widen both sides to three hours and it falls to 34%. The figure depends on the window, so it is quoted here with one. Traffic is near nil, and to almost nothing after that. In the one to three hours past sunset the median transit was 17 minutes — the lowest median anywhere in the archive, against 28 minutes in the late afternoon. That sample is 26 lockages, so treat it as indicative rather than precise.

The chamber itself gets faster

This was not expected. Splitting transit into its two parts — the queue, and the lockage itself — shows the chamber speeding up after dark:

Relative to sunsetQueueChamberTransit
6–2 hours before5 min18 min25 min
2–0 hours before5 min15 min20 min
0–2 hours after6 min14 min23 min
1–3 hours after4 min13 min17 min

Eighteen minutes in the afternoon, thirteen after dark — five minutes off the part of the transit that is usually described, including on this site until we checked, as the irreducible bit. It is not irreducible. It is just busier during the day.

The obvious explanation is one we cannot test. A chamber holding two boats should load, tie off and empty faster than one holding five, and there are far fewer boats about at night — so fewer boats per lockage is the natural reading. But the Corps logs recreational traffic as anonymous grouped records with no vessel count, so the number of boats in any given chamber is not in the data. The speed-up is measured; the cause is a hypothesis, and we are not going to state it as more than that.

But the improvement arrives before the boats leave

Look at the third row of that table again. The median transit is already down to 20 minutes in the two hours before sunset — while recreational traffic is still running at 1.78 lockages an hour, essentially its full daytime rate.

The transit time improves before the crowd goes home. So the crowd going home is not what improves it.

What actually changes at dusk is the commercial fleet. Commercial lockages fall from 0.77 an hour in the late afternoon to 0.34, then to 0.21 after sunset. On 16 of the 30 days measured the last commercial lockage of the day happened before sunset. Because commercial vessels take the small lock to themselves and hold federal priority under 33 CFR 207.750, one ahead of you costs a full cycle — so when the tugs and tour boats knock off, the queue relaxes while pleasure boats are still arriving at full rate.

This is the same pattern that runs through everything else measured here. Recreational arrivals are nearly constant through daylight — hour-to-hour variation of only about 14%, against more than 60% for commercial (measured hour by hour on the wait-times page). You are almost never dodging other pleasure boats. You are dodging commercial vessels, and the cycle luck they create.

The practical consequence: you do not have to wait for dark. Most of the evening gain is available in the last couple of hours of daylight, once the commercial day has wound down. Waiting a further two hours for full dark buys perhaps three more minutes, at the cost of handling lines in the dark.

Does the evening quiet move with sunset through the year?

This matters more than it sounds. Seattle sunset falls around 20:48 in late July and around 16:20 in December. If the evening lull is driven by darkness, it arrives at half past four in winter. If it is driven by the clock — dinner, bedtime, work in the morning — it stays put at nine in the evening all year, and a boater planning a December passage from summer figures would be four hours wrong.

The archive contains a small natural experiment: sunset moved 51 minutes earlier across the month measured. Splitting the month in half, normalising for a 4% seasonal decline in overall traffic, and asking which index makes the two halves agree:

Clock hour fits better, by about 21%. That points toward boaters going home on a domestic schedule rather than by the light.

We are not claiming this. Fifty-one minutes of drift across 30 days is not enough to separate two variables that closely related, and the gap between the two fits is small enough to be noise. What the data supports is: the evening drop is real and large, and there is currently no evidence it tracks sunset rather than the clock. A winter archive settles it — a 4.5-hour swing in sunset cannot be confused with anything — and we will publish the answer when there is one, whichever way it falls.

What is worth knowing if you do lock through at night

The honest limit on all of this

One month is one month, and it is a high-summer month. Every figure here describes 30 July to 28 August 2026. August evenings are warm and light until nearly nine; November evenings are neither, and the traffic behaves differently for reasons that have nothing to do with lock operations. Nothing on this page should be read as a year-round claim, and where a sample is small it is stated so you can judge it yourself.

These are measured figures for the window stated, not a live reading. Current conditions — including how tonight is actually running — are on the live forecast.

Common questions

Can you go through the Ballard Locks at night?
Yes. Twenty-four hours a day, year round, on demand, with no timetable and no fee. Attendants are on duty overnight and VHF channel 13 is staffed 24 hours.
Are the Ballard Locks quieter after dark?
Substantially. Recreational traffic falls from about 1.7–1.9 lockages an hour through the afternoon to about 0.8 in the two hours after sunset, and about 0.1 beyond that — 48% of the pre-sunset rate comparing two hours either side of sunset, 34% comparing three. Beyond that, almost nothing.
Is the wait shorter at night?
Yes, and it is the shortest measured: a median transit of 17 minutes in the one to three hours after sunset, against 28 in the late afternoon (n=26, so indicative). But most of that gain is already available before sunset.
Why does the evening transit time improve?
Commercial traffic stops, not recreational traffic. On 16 of the 30 days measured the last commercial lockage happened before sunset, and commercial vessels take the small lock alone under federal priority — so their departure relieves the queue while pleasure boats are still arriving at full rate.
Does the evening lull shift earlier in winter?
Unknown. Clock hour fitted the evening drop slightly better than sunset time over the month measured, hinting the lull is schedule-driven rather than light-driven, but one month of summer cannot settle it. A winter archive will.