Flight number record
AS 734
Alaska Airlines · Salt Lake City to Seattle
- Route
- SLC → SEA
- Departs
- 15:39
- Flights
- 276
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s AS 734, check with Alaska Airlines.
AS 734 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 276 flights, with a median arrival right on schedule.
The national on-time rate over the same period is 77.6%, so AS 734 runs 11 points behind the country as a whole. Across a thousand flights that is about 113 extra late arrivals.
Key figures
On time
66.3%
Arrivals under 15 minutes late, of 273 completed flights
Avg delay
42 min
Across delayed arrivals only, not all flights
Cancelled
1.09%
National rate is 1.81%
1 hour+ late
4.8%
National rate is 8.1%
These figures cover 276 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 734 flies
AS 734 flies SLC to SEA without a single fixed slot. Its most common scheduled departure was 15:39, used on 70 of 276 flights, with 15:29 (45 flights) and 09:00 (35 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 15:3970 flights25.4%
- Departs 15:2945 flights16.3%
- Departs 09:0035 flights12.7%
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 15:39 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 72.4%, and AS 734 runs 6 points worse at 66.3%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
Against the route
AS 734 next to SLC to SEA
Every carrier on SLC to SEA combined arrived on time 80.2% of the time across 4,108 flights, so AS 734 is 14 points behind it. Alaska flew 1,369 flights on the same city pair under all its flight numbers, including this one, and those ran 76.7% on time. Across its whole network Alaska Airlines managed 79.1%, which this flight trails by 13 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| AS 734thin sample | 276 | 66.3% | 42 min | 1.09% | C |
| All Alaska Airlines on SLC–SEA | 1,369 | 76.7% | 46 min | 1.83% | B |
| All carriers on SLC–SEA | 4,108 | 80.2% | 53 min | 0.97% | B+ |
| Alaska Airlines, whole network | 293,372 | 79.1% | 52 min | 1.28% | B |
Across the year
AS 734 quarter by quarter
AS 734 did not run the same all year. Its best quarter was Apr–Jun 2026 at 81.0% on time and its weakest Jul–Sep 2025 at 56.0%, a swing of 25 points on roughly 69 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 flights56.0%
- Oct–Dec 202587 flights72.9%
- Jan–Mar 202655 flights61.8%
- Apr–Jun 202642 flights81.0%
Scale runs 50% to 85%. Rows with fewer than 30 flights show a dash.
By weekday, AS 734 did best on Saturday at 76.5% on time and worst on Monday at 52.5%. Each day rests on about 39 flights, so a gap of 24 points is worth noticing but could still narrow in another year.
Delay causes
Why AS 734 runs late
One category carries most of the weight here. Late-arriving aircraft accounts for 61% of the 3,818 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 61%Late-arriving aircraft
- 31%National Airspace System
- 8%Carrier
- 0%Security
61% 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 3,818 reported delay minutes here, that single category outweighs weather by 61 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 3,818 delay minutes reported on AS 734.
Cancellations sit at 1.09% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 4.8% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
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 SEA to OAK (49) and ANC to PDX (34), but none flew often enough under AS 734 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SLC to SEA only.
One caution: this is a thin sample. 276 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 734
For a booking, AS 734 is one of the weaker ways to fly SLC to SEA: 14 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
- SLC to SEA, every carrier and departure
- SEA to SLC, the return direction
- Delta Air Lines 2995 on the same route89.0%
- Delta Air Lines 2874 on the same route91.8%
- Delta Air Lines 2817 on the same route75.1%
- Delta Air Lines 871 on the same route82.1%
- Delta Air Lines 2921 on the same route84.6%
- Alaska Airlines 796 on the same route84.7%
- Salt Lake City International (SLC) delay statistics
- Seattle-Tacoma International (SEA) delay statistics
- Alaska Airlines on-time record
- Every Alaska Airlines flight number with a record
- The most and least reliable flight numbers in the US
- Why the first flight of the morning is statistically safest
A flight number here means Alaska Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
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.