Flight number record
AS 602
Alaska Airlines · Seattle to Denver
- Route
- SEA → DEN
- Departs
- 15:49
- Flights
- 280
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s AS 602, check with Alaska Airlines.
AS 602 sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 5 points worse than the national rate of 77.6%. The late ones land roughly 50 minutes behind schedule. That rests on 280 flights, with a median arrival 2 minutes early.
The national on-time rate over the same period is 77.6%, so AS 602 runs 5 points behind the country as a whole. Across a thousand flights that is about 49 extra late arrivals.
Key figures
On time
72.7%
Arrivals under 15 minutes late, of 278 completed flights
Avg delay
49 min
Across delayed arrivals only, not all flights
Cancelled
0.36%
National rate is 1.81%
1 hour+ late
6.8%
National rate is 8.1%
These figures cover 280 flights between July 2025 and June 2026. The median arrival is 2 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Schedule
When AS 602 flies
AS 602 flies SEA to DEN without a single fixed slot. Its most common scheduled departure was 15:49, used on 42 of 280 flights, with 16:40 (39 flights) and 19:54 (36 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 15:4942 flights15.0%
- Departs 16:4039 flights13.9%
- Departs 19:5436 flights12.9%
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 15:49 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 72.4%, and AS 602 runs level with that at 72.7%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
Against the route
AS 602 next to SEA to DEN
Every carrier on SEA to DEN combined arrived on time 77.8% of the time across 6,317 flights, so AS 602 is 5 points behind it. Alaska flew 1,558 flights on the same city pair under all its flight numbers, including this one, and those ran 75.9% on time. Across its whole network Alaska Airlines managed 79.1%, which this flight trails by 6 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| AS 602thin sample | 280 | 72.7% | 49 min | 0.36% | C+ |
| All Alaska Airlines on SEA–DEN | 1,558 | 75.9% | 50 min | 0.83% | B+ |
| All carriers on SEA–DEN | 6,317 | 77.8% | 58 min | 0.85% | B+ |
| Alaska Airlines, whole network | 293,372 | 79.1% | 52 min | 1.28% | B |
Across the year
AS 602 quarter by quarter
AS 602 did not run the same all year. Its best quarter was Oct–Dec 2025 at 85.3% on time and its weakest Jul–Sep 2025 at 48.1%, a swing of 37 points on roughly 70 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 202578 flights48.1%
- Oct–Dec 202568 flights85.3%
- Jan–Mar 202665 flights78.1%
- Apr–Jun 202669 flights82.6%
Scale runs 40% to 90%. Rows with fewer than 30 flights show a dash.
By weekday, AS 602 did best on Tuesday at 82.1% on time and worst on Sunday at 62.8%. Each day rests on about 40 flights, so a gap of 19 points is worth noticing but could still narrow in another year.
Delay causes
Why AS 602 runs late
One category carries most of the weight here. National Airspace System accounts for 42% of the 3,719 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.
- 42%National Airspace System
- 33%Late-arriving aircraft
- 15%Carrier
- 10%Extreme weather
42% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 1,565 minutes out of 3,719, against a national NAS share of 21%. The split is drawn from 3,719 delay minutes reported on AS 602.
Cancellations are rare at 0.36%, 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
6.8% 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 50 minutes, which a normal layover absorbs.
The 1,024 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 one other city pair in the data, including LAX to SFO (1), but none flew often enough under AS 602 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SEA to DEN only.
One caution: this is a thin sample. 280 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 602
For a booking, AS 602 is one of the weaker ways to fly SEA to DEN: 5 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
- SEA to DEN, every carrier and departure
- DEN to SEA, the return direction
- United Airlines 757 on the same route85.5%
- Alaska Airlines 682 on the same route83.8%
- United Airlines 1505 on the same route91.0%
- Frontier Airlines 3406 on the same route75.6%
- Seattle-Tacoma International (SEA) delay statistics
- Denver International (DEN) 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.