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DelayAtlas

Flight number record

AS 733

Alaska Airlines · Seattle to Salt Lake City

Route
SEA → SLC
Departs
11:38
Flights
271
Period
July 2025 to June 2026
C+GRADE

Historical statistics for July 2025 to June 2026, not live status. For today’s AS 733, check with Alaska Airlines.

AS 733 draws a C+. About one flight in three arrives at least 15 minutes late, and the typical late arrival is roughly 40 minutes behind schedule. Build slack into anything you connect to. That rests on 271 flights, with a median arrival 1 minute late.

The national on-time rate over the same period is 77.6%, so AS 733 runs 11 points behind the country as a whole. Across a thousand flights that is about 114 extra late arrivals.

Key figures

On time

66.2%

Arrivals under 15 minutes late, of 269 completed flights

Avg delay

41 min

Across delayed arrivals only, not all flights

Cancelled

0.74%

National rate is 1.81%

1 hour+ late

5.6%

National rate is 8.1%

These figures cover 271 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.

Schedule

When AS 733 flies

AS 733 flies SEA to SLC without a single fixed slot. Its most common scheduled departure was 11:38, used on 50 of 271 flights, with 11:20 (33 flights) and 12:03 (29 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

  • Departs 11:3850 flights18.5%
  • Departs 11:2033 flights12.2%
  • Departs 12:0329 flights10.7%

Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.

Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.

A 11:38 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.8%, and AS 733 runs 13 points worse at 66.2%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

AS 733 next to SEA to SLC

Every carrier on SEA to SLC combined arrived on time 83.6% of the time across 4,107 flights, so AS 733 is 17 points behind it. Alaska flew 1,372 flights on the same city pair under all its flight numbers, including this one, and those ran 79.6% on time. Across its whole network Alaska Airlines managed 79.1%, which this flight trails by 13 points.

AS 733 against its route and carrier
Compared withFlightsOn timeAvg delayCancelledGrade
AS 733thin sample27166.2%41 min0.74%C+
All Alaska Airlines on SEA–SLC1,37279.6%41 min1.68%B
All carriers on SEA–SLC4,10783.6%50 min0.93%B+
Alaska Airlines, whole network293,37279.1%52 min1.28%B

Across the year

AS 733 quarter by quarter

AS 733 did not run the same all year. Its best quarter was Apr–Jun 2026 at 78.6% on time and its weakest Jul–Sep 2025 at 56.5%, a swing of 22 points on roughly 68 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.

  • Jul–Sep 202592 flights56.5%
  • Oct–Dec 202587 flights70.6%
  • Jan–Mar 202650 flights66.0%
  • Apr–Jun 202642 flights78.6%

Scale runs 50% to 85%. Rows with fewer than 30 flights show a dash.

By weekday, AS 733 did best on Wednesday at 72.5% on time and worst on Monday at 55.0%. Each day rests on about 39 flights, so a gap of 18 points is worth noticing but could still narrow in another year.

On-time rate by day of the week55.0Mon70.7Tue72.5Wed67.5Thu69.2Fri70.0Sat59.0Sun
Monday: 55.0 percent on time. Tuesday: 70.7 percent on time. Wednesday: 72.5 percent on time. Thursday: 67.5 percent on time. Friday: 69.2 percent on time. Saturday: 70.0 percent on time. Sunday: 59.0 percent on time

Delay causes

Why AS 733 runs late

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 3,761 reported delay minutes.

  • Carrier
    41%
  • Late-arriving aircraft
    41%
  • National Airspace System
    16%
  • Security
    1%

41% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 3,761 reported delay minutes here, that single category outweighs weather by 41 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 3,761 delay minutes reported on AS 733.

Cancellations are rare at 0.74%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

Connections and routes

What a delay on this flight costs

5.6% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last roughly 40 minutes, which a normal layover absorbs.

The 689 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

The same number turns up on two other city pairs in the data, including OAK to SEA (49) and PDX to ANC (34), but none flew often enough under AS 733 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SEA to SLC only.

One caution: this is a thin sample. 271 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.

What to do with this

Booking AS 733

For a booking, AS 733 is one of the weaker ways to fly SEA to SLC: 17 points below the route as a whole. If the schedule allows, compare it with the other departures listed on the route page before settling on this one.

Related

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.