Route profile
ATL→SEA
Flight reliability, delays and best times to fly from Atlanta to Seattle, 2,182 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 76% of comparable major US routes (4,598 compared)
Calculated from 10,595 flights. How this is calculated
ATL → SEA arrives on time 80.0% of the time; the return trip, SEA → ATL, arrives on time 81.8% of the time.
ATL → SEA spends 30.3 minutes on the ground on a 2,182-mile trip: 17.8 minutes from pushback to wheels-up at ATL and 12.5 minutes from touchdown to gate at SEA.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
Why ATL → SEA flights are cancelled
July 2023 – July 2026
ATL → SEA cancelled 86 of 10,595 scheduled flights — about 1 in every 123. The reason filed most often was the airline, 72.1% of the cancellations coded on this route — about 1 in every 171 scheduled flights.
Share of cancellations
Of 86 cancelled departures carrying a reason code.
What each reason means
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
62 cancellations, 72.1% of the total.
Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.
24 cancellations, 27.9% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
0 cancellations, 0.0% of the total.
A terminal evacuation, a security breach, screening equipment failure, or screening queues over 29 minutes.
0 cancellations, 0.0% of the total.
Reason codes are the operating airline’s own filing with US DOT, not an independent finding of fault. With only one or two carriers on the route, the split mostly reflects how they file. Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.
86 coded cancellations were recorded on ATL → SEA; the section appears from 50.
When it goes wrong
July 2023 – July 2026
33 min late
against a median of 7 min early
Percentiles over 10,595 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at SEA after arriving from ATL.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 37% | Likely to miss |
| 45 min | 19% | High risk |
| 60 min | 11% | Some risk |
| 90 min | 4.9% | Low risk |
| 120 min | 2.8% | Low risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 0.81% of the time and diverts 0.21% of the time, which a late arrival never shows up in.
Chance of missing is the share of 10,487 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 33 minutes late (90th-percentile gate arrival delay), over 10,595 operations.
Any other layover length: connection checker.
Best time to fly
ATL → SEA flights departing 5–9 AM arrived on time 86.9% of the time, against 66.2% for 6–9 PM departures, a gap of 20.7 percentage points.
By departure window
By departure hour
- 12 AM to 5 AM: too few flights to score
- 6 AM: 89.6% on time from 127 flights
- 7 AM: 88.2% on time from 1,609 flights
- 8 AM: 82.5% on time from 548 flights
- 9 AM: 80.9% on time from 1,576 flights
- 10 AM: 82.9% on time from 129 flights
- 11 AM: 86.6% on time from 659 flights
- 12 PM: 84.0% on time from 674 flights
- 1 PM: 88.2% on time from 436 flights
- 2 PM: 83.4% on time from 339 flights
- 3 PM: 80.8% on time from 568 flights
- 4 PM: 75.1% on time from 797 flights
- 5 PM: 77.2% on time from 472 flights
- 6 PM: 75.4% on time from 415 flights
- 7 PM: 62.5% on time from 1,254 flights
- 8 PM: 72.5% on time from 120 flights
- 9 PM: 79.8% on time from 846 flights
- 10 PM to 11 PM: too few flights to score
Why ATL → SEA runs late
July 2023 – July 2026
crew, maintenance, boarding and fueling, all 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 ATL → SEA. Only delays of 15 minutes or more are attributed.
How this route holds up in bad weather
July 2023 – July 2026
The harder-hit end is the one the flight leaves from, where a cancellation keeps it from departing at all. Bad weather cancels 3.3 times the normal rate at ATL against 1.9 times at SEA. Cancelled in bad weather against normal hours: ATL 3.4% against 1.0%, SEA 1.5% against 0.8%. Flights that did leave ATL in bad weather arrived on time 66.5% of the time, against 80.2% in normal hours.
Bad weather and normal hours at the airports
Scheduled departures, July 2023 – July 2026| Departures from | ATL | SEA |
|---|---|---|
| Cancelled in bad weather | 3.4% | 1.5% |
| Cancelled in normal hours | 1.0% | 0.8% |
| Arrived on time, bad weather | 66.5% | 75.4% |
| Arrived on time, normal hours | 80.2% | 79.3% |
| Departures in bad weather | 105,854 | 43,416 |
These are airport figures, not route figures: every scheduled departure from ATL and SEA, to any destination, in hours the weather report called bad.
Weather source and limits. In full: ATL, SEA, What Weather Costs Each Airport, Who Cancels More When the Weather Turns, Airports That Change Places When Weather Turns.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| Delta Air Lines | 7,457 | 81.6% | 0.66% | -8 min | 4.7% |
| Alaska Airlines | 3,138 | 76.2% | 1.18% | -4 min | 5.5% |
Delta Air Lines flew 70.4% of the 10,595 flights listed.
Delta Air Lines arrived on time 5.4 percentage points more often than Alaska Airlines on this route.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
DL629 (12:15 PM) arrived on time 86.6% of the time, 8.2 points more often than DL903 (9:25 PM) at 78.4%.
Weekly and seasonal patterns
By day of week
Wednesday is historically the most reliable day and Sunday the least, a gap of 5.4 percentage points.
By month
- Jan: 79.1%
- Feb: 79.7%
- Mar: 81.2%
- Apr: 84.1%
- May: 75.1%
- Jun: 73.6%
- Jul: 68.5%
- Aug: 79.2%
- Sep: 87.9%
- Oct: 89.0%
- Nov: 90.0%
- Dec: 81.1%
July is historically the weakest month and November the strongest, a spread of 21.5 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 60.9% from 372 flights
- August 2023: 79.7% from 380 flights
- September 2023: 89.1% from 322 flights
- October 2023: 90.1% from 314 flights
- November 2023: 92.6% from 287 flights
- December 2023: 93.4% from 273 flights
- January 2024: 85.3% from 233 flights
- February 2024: 90.5% from 211 flights
- March 2024: 92.4% from 251 flights
- April 2024: 85.5% from 269 flights
- May 2024: 70.5% from 312 flights
- June 2024: 73.3% from 348 flights
- July 2024: 67.3% from 377 flights
- August 2024: 81.0% from 374 flights
- September 2024: 85.7% from 330 flights
- October 2024: 95.0% from 299 flights
- November 2024: 92.4% from 263 flights
- December 2024: 88.5% from 270 flights
- January 2025: 78.3% from 215 flights
- February 2025: 71.7% from 184 flights
- March 2025: 80.6% from 223 flights
- April 2025: 78.4% from 244 flights
- May 2025: 78.4% from 291 flights
- June 2025: 70.9% from 328 flights
- July 2025: 78.0% from 347 flights
- August 2025: 76.4% from 315 flights
- September 2025: 89.0% from 283 flights
- October 2025: 81.8% from 295 flights
- November 2025: 84.7% from 257 flights
- December 2025: 61.1% from 269 flights
- January 2026: 73.5% from 214 flights
- February 2026: 75.4% from 193 flights
- March 2026: 69.5% from 232 flights
- April 2026: 88.0% from 252 flights
- May 2026: 76.7% from 296 flights
- June 2026: 76.7% from 324 flights
- July 2026: 68.5% from 348 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 76.7% against 81.8% in the 12 months before — declining by 5.1 percentage points.
Data and methodology
Calculated by FlyerIntel from 10,595 ATL → SEA flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed