Flight profile · Delta Air Lines
DL629
Atlanta (ATL) to Seattle (SEA) · scheduled 12:15 PM – 2:18 PM
How DL629 performs
973 operations, 2023-09-05 to 2026-06-30.
DL629 arrived on time 86.6% of the time, against 80.4% for all ATL → SEA flights — this specific departure is 6.2 percentage points better than the route as a whole. Against Delta Air Lines’s own flights on this route it is 4.4 points better.
Source: US DOT Bureau of Transportation Statistics · 973 operations between 2023-09-05 to 2026-06-30
Against the rest of the route
| On time | Cancelled | Median delay | Severe | Flights | |
|---|---|---|---|---|---|
| DL629 | 86.6% | 0.41% | -11 min | 2.7% | 973 |
| Delta Air Lines on ATL → SEA | 82.1% | 0.67% | -8 min | 4.4% | 7,193 |
| All ATL → SEA flights | 80.4% | 0.82% | -7 min | 4.8% | 10,247 |
Source: FlyerIntel analysis of US DOT BTS data · 2023-09-05 to 2026-06-30
By day of week
Does DL629 run worse on particular days?
Sunday is historically the most reliable day and Tuesday the least, a gap of 5.6 percentage points.
Source: FlyerIntel analysis of US DOT BTS data · 2023-09-05 to 2026-06-30 · Days with fewer than 120 operations are not scored.
Other routes DL629 has flown
A flight number is a slot in a schedule, and carriers reassign it. These are the other city pairs this number served in the analysis period.
Because the same number has served different journeys, the statistics above describe only the route DL629 currently operates. Blending them would produce an average of two different flights.
Why DL629 runs late
Where US DOT attributed the delay minutes on this flight.
crew, maintenance, boarding, fuelling — within the carrier’s control
airspace and airport capacity, including weather-driven flow control
the inbound aircraft was late, so this flight started late
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for DL629 on ATL → SEA. A single late flight can carry more than one cause, and only delays of fifteen minutes or more are attributed at all.
Other departures on ATL → SEA
Same airports, same journey — and not the same odds of arriving on time.
| Flight | Airline | On time | Median arrival | Operations |
|---|---|---|---|---|
| DL444 | Delta Air Lines | 86.5% | 11 min early | 870 |
| AS377 | Alaska Airlines | 85.6% | 9 min early | 963 |
| DL774 | Delta Air Lines | 84.3% | 9 min early | 1,096 |
| DL903 | Delta Air Lines | 79.1% | 8 min early | 741 |
Every departure listed carries at least 600 operations, so the comparison is between figures that mean something. Schedules change; confirm the departure still operates before booking around this.
Data and methodology
Calculated by FlyerIntel from 973 records of DL629 operating ATL → 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.
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