Flight number record
AS 602
Alaska Airlines · Seattle to Denver
- Route
- SEA → DEN
- Departs
- 16:26
- Flights
- 290
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 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+. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.3%. The late ones land roughly 50 minutes behind schedule. That rests on 290 flights, with a median arrival 2 minutes early.
Key figures
On time
74.7%
Arrivals under 15 minutes late, of 288 completed flights
Avg delay
48 min
Across delayed arrivals only, not all flights
Cancelled
0.34%
National rate is 1.89%
1 hour+ late
4.5%
National rate is 8.3%
These figures cover 290 flights between September 2025 and August 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.
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Schedule
When AS 602 flies
AS 602 flies SEA to DEN without a single fixed slot. Its most common scheduled departure was 16:26, used on 59 of 290 flights, with 19:54 (36 flights) and 16:40 (29 flights) next.
- Departs 16:2659 flights20.3%
- Departs 19:5436 flights12.4%
- Departs 16:4029 flights10.0%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 16:26 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 71.9%, and AS 602 runs 3 points better at 74.7%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
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Against the route
AS 602 next to SEA to DEN
Every carrier on SEA to DEN combined arrived on time 78.3% of the time across 6,333 flights, so AS 602 is 4 points behind it. Alaska flew 1,552 flights on the same city pair under all its flight numbers, including this one, and those ran 78.2% on time. Across its whole network Alaska Airlines managed 79.7%, which this flight trails by 5 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| AS 602thin sample | 290 | 74.7% | 48 min | 0.34% | C+ |
| All Alaska Airlines on SEA–DEN | 1,552 | 78.2% | 48 min | 0.64% | B+ |
| All carriers on SEA–DEN | 6,333 | 78.3% | 58 min | 0.68% | B+ |
| Alaska Airlines, whole network | 309,844 | 79.7% | 52 min | 1.20% | 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 2026 at 49.2%, a swing of 36 points on roughly 73 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 202526 flights—
- Oct–Dec 202568 flights85.3%
- Jan–Mar 202665 flights78.1%
- Apr–Jun 202669 flights82.6%
- Jul–Sep 202662 flights49.2%
Scale runs 40% to 90%. Rows with fewer than 30 flights show a dash.
By weekday, AS 602 did best on Wednesday at 84.6% on time and worst on Thursday at 66.7%. Each day rests on about 41 flights, so a gap of 18 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late AS 602 runs when it is late
The 73 late arrivals split 26 under half an hour, 34 between 30 and 60 minutes, and 13 an hour or more.
- 15+ min early67 flights23.3%
- Within 15 min148 flights51.4%
- 15–29 min late26 flights9.0%
- 30–59 min late34 flights11.8%
- 1–2 hours late9 flights3.1%
- 2+ hours late4 flights1.4%
Scale runs 0% to 100%.
Share of 288 completed flights by arrival against schedule.
22 of 81 late departures made up the time and arrived on time, 27% of them. 14 flights left on time and still arrived late.
The worst days
Worst days for AS 602
The latest arrival of the period was on 29 July 2026, 3 hours 39 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. On three of the five worst days the largest share was filed as national airspace system delay.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 29 July 2026 | 3 hours 39 minutes | Late-arriving aircraft |
| 22 July 2026 | 3 hours 3 minutes | National Airspace System |
| 27 December 2025 | 2 hours 25 minutes | Late-arriving aircraft |
| 22 September 2025 | 2 hours 1 minute | National Airspace System |
| 15 August 2026 | 1 hour 55 minutes | National Airspace System |
Delay causes
Why AS 602 runs late
National Airspace System accounts for 49% of the 3,531 delay minutes carriers reported here, and the remaining four split what is left.
- 49%National Airspace System
- 31%Late-arriving aircraft
- 13%Carrier
- 6%Extreme weather
49% 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 1,746 minutes out of 3,531, against a national NAS share of 21%. The split is drawn from 3,531 delay minutes reported on AS 602.
Cancellations are rare at 0.34%, below the national 1.89% 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
Badly late arrivals are rare here: only 4.5% land an hour or more behind schedule, against 8.3% 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 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.
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. 290 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, read AS 602 as 74.7% on time with 0.34% cancelled over 290 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- SEA to DEN, every carrier and departure
- DEN to SEA, the return direction
- United Airlines 757 on the same route85.4%
- United Airlines 1505 on the same route91.1%
- Frontier Airlines 3406 on the same route75.0%
- Alaska Airlines 682 on the same route86.1%
- Delta Air Lines 2851 on the same route76.1%
- 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
- The best time of day to fly, according to 7.05 million flight records
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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.