Flight Reliability
AS 4 · Alaska Airlines
Seattle → Washington (SEA–DCA)
80
Pretty Reliable
WanderNerd Reliability Score
- 85%
- Arrive within 15 minutes
- 6 min early
- Average arrival delay
- 1.1%
- Cancelled
- 12 min early
- Median arrival delay
Based on 365 historical flights. Data through May 2026.
What the data says
Mondays have been rough.
AS 4 arrived on time 94% of the time on Wednesdays and just 77% on Mondays. That gap is worth planning around.
A bit ahead of the SEA–DCA route.
AS 4 arrived on time 85% of the time, versus 81% across the SEA–DCA route.
A bit ahead of the Alaska Airlines network.
AS 4 arrived on time 85% of the time, versus 80% across the Alaska Airlines network.
Trending in the right direction.
AS 4 arrived on time 91% of the time over the last three months in the data, compared with 84% in the three months before that.
The breakdown
- Mon77%(51 flights)
- Tue86%(50 flights)
- Wed94%(51 flights)
- Thu78%(50 flights)
- Fri84%(50 flights)
- Sat94%(51 flights)
- Sun80%(50 flights)
97%
May
Jun 76% → May 97% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 76% | 29 |
| July 2025 | 84% | 25 |
| August 2025 | 93% | 29 |
| September 2025 | 72% | 29 |
| October 2025 | 81% | 31 |
| November 2025 | 83% | 30 |
| December 2025 | 90% | 31 |
| January 2026 | 87% | 30 |
| February 2026 | 75% | 28 |
| March 2026 | 87% | 30 |
| April 2026 | 90% | 30 |
| May 2026 | 97% | 31 |
- Departures on time
- 85%
- Diverted
- 2.2%
- Flights flown
- 353
- Months covered
- 12
Same route, other flights
Keep nerding
Based on 365 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.