Flight profile · Alaska Airlines
AS643
Denver (DEN) to Seattle (SEA) · scheduled 6:00 AM – 8:05 AM
How AS643 performs
959 operations, 2023-07-01 to 2026-06-30.
AS643 arrived on time 88.2% of the time, against 74.9% for all DEN → SEA flights — this specific departure is 13.4 percentage points better than the route as a whole. Against Alaska Airlines’s own flights on this route it is 12.9 points better.
Source: US DOT Bureau of Transportation Statistics · 959 operations between 2023-07-01 to 2026-06-30
Against the rest of the route
| On time | Cancelled | Median delay | Severe | Flights | |
|---|---|---|---|---|---|
| AS643 | 88.2% | 0.63% | -10 min | 3.6% | 959 |
| Alaska Airlines on DEN → SEA | 75.3% | 0.95% | -4 min | 6.7% | 4,733 |
| All DEN → SEA flights | 74.9% | 0.67% | -3 min | 7.3% | 19,612 |
Source: FlyerIntel analysis of US DOT BTS data · 2023-07-01 to 2026-06-30
By day of week
Does AS643 run worse on particular days?
Tuesday is historically the most reliable day and Sunday the least, a gap of 5.0 percentage points.
Source: FlyerIntel analysis of US DOT BTS data · 2023-07-01 to 2026-06-30 · Days with fewer than 120 operations are not scored.
Data and methodology
Calculated by FlyerIntel from 959 records of AS643 operating DEN → SEA, published by the US DOT Bureau of Transportation Statistics. A flight counts as delayed when it arrives 15 or more minutes after schedule. Cancelled and diverted flights are excluded from the on-time rate and reported separately. Flight numbers are resolved as carrier plus number plus route, because the same number serves different routes over time.