Flight number record
AS 4
Alaska Airlines · Seattle to Washington
- Route
- SEA → DCA
- Departs
- 08:00
- Flights
- 364
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s AS 4, check with Alaska Airlines.
AS 4 earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.3%. When something does go wrong the average delay runs roughly 45 minutes. That rests on 364 flights, with a median arrival 18 minutes early.
Set against the rest of the country, AS 4's record is 8 points better than the US average of 77.3%. That gap is worth roughly 79 fewer late arrivals for every thousand flights.
Key figures
On time
85.2%
Arrivals under 15 minutes late, of 359 completed flights
Avg delay
46 min
Across delayed arrivals only, not all flights
Cancelled
0.27%
National rate is 1.89%
1 hour+ late
3.6%
National rate is 8.3%
These figures cover 364 flights between September 2025 and August 2026. The median arrival is 18 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 4 flies
AS 4 flies SEA to DCA without a single fixed slot. Its most common scheduled departure was 08:00, used on 283 of 364 flights.
- Departs 08:00283 flights77.7%
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 08:00 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and AS 4 runs level with that at 85.2%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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Against the route
AS 4 next to SEA to DCA
Every carrier on SEA to DCA combined arrived on time 82.6% of the time across 1,092 flights, so AS 4 is 3 points ahead of it. Alaska flew 728 flights on the same city pair under all its flight numbers, including this one, and those ran 78.0% on time. Across its whole network Alaska Airlines managed 79.7%, which this flight beats by 6 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| AS 4thin sample | 364 | 85.2% | 46 min | 0.27% | A+ |
| All Alaska Airlines on SEA–DCA | 728 | 78.0% | 54 min | 0.69% | B+ |
| All carriers on SEA–DCA | 1,092 | 82.6% | 64 min | 1.37% | B |
| Alaska Airlines, whole network | 309,844 | 79.7% | 52 min | 1.20% | B |
Across the year
AS 4 quarter by quarter
AS 4 did not run the same all year. Its best quarter was Apr–Jun 2026 at 93.4% on time and its weakest Jan–Mar 2026 at 83.0%, a swing of 10 points on roughly 91 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 202530 flights—
- Oct–Dec 202592 flights84.8%
- Jan–Mar 202690 flights83.0%
- Apr–Jun 202691 flights93.4%
- Jul–Sep 202661 flights84.7%
Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.
By weekday, AS 4 did best on Wednesday at 96.2% on time and worst on Monday at 77.4%. Each day rests on about 52 flights, so a gap of 19 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late AS 4 runs when it is late
AS 4 often beats the schedule: 203 of 359 completed flights, 57%, arrived 15 minutes or more early. The 53 late arrivals split 22 under half an hour, 18 between 30 and 60 minutes, and 13 an hour or more.
- 15+ min early203 flights56.5%
- Within 15 min103 flights28.7%
- 15–29 min late22 flights6.1%
- 30–59 min late18 flights5.0%
- 1–2 hours late9 flights2.5%
- 2+ hours late4 flights1.1%
Scale runs 0% to 100%.
Share of 359 completed flights by arrival against schedule.
13 of 55 late departures made up the time and arrived on time, 24% of them. 11 flights left on time and still arrived late.
The worst days
Worst days for AS 4
The latest arrival of the period was on 26 January 2026, 3 hours 25 minutes behind schedule; most of its delay minutes were filed as extreme weather. The five worst days are spread across January, November and October, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 26 January 2026 | 3 hours 25 minutes | Extreme weather |
| 9 November 2025 | 2 hours 24 minutes | Carrier |
| 7 November 2025 | 2 hours 15 minutes | National Airspace System |
| 3 October 2025 | 2 hours 7 minutes | Carrier |
| 30 October 2025 | 1 hour 16 minutes | Extreme weather |
Delay causes
Why AS 4 runs late
National Airspace System accounts for 44% of the 2,446 delay minutes carriers reported here, and the remaining four split what is left.
- 44%National Airspace System
- 38%Carrier
- 17%Extreme weather
- 2%Late-arriving aircraft
Extreme weather accounts for 17% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the quarterly figures above are the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.8 times the usual weather exposure. The split is drawn from 2,446 delay minutes reported on AS 4.
Cancellations are rare at 0.27%, 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 3.6% 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.
At 2,329 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
Every one of the 364 flights under AS 4 in the data flew SEA to DCA. The number was not reused on any other city pair, which makes this a clean record of one route.
One caution: this is a thin sample. 364 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 4
For a booking, AS 4 has one of the better records a US domestic flight can show: 85.2% on time and 0.27% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- SEA to DCA, every carrier and departure
- DCA to SEA, the return direction
- Alaska Airlines 2 on the same route70.6%
- Delta Air Lines 786 on the same route91.0%
- Seattle-Tacoma International (SEA) delay statistics
- Ronald Reagan Washington National (DCA) 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
- Worst months to fly in the US, ranked by the data
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.