Seattle (SEA) to Salt Lake City (SLC): On-Time Performance
Data through July 2026
The calendar drives reliability on SEA–SLC. April 2026 flights landed on schedule 92% of the time, but July 2024 dropped to 75% — a gap of 17 points. Across the full period the route averages 83% on-time against a national 78%.
- On-time
- 83%
- arrived <15 min late
- Avg delay
- 10 min
- completed flights
- Cancelled
- 0.7%
- Flights/day
- 11
- last 12 months
- Duration
- 2h 6m
- scheduled
- Distance
- 689 mi
Best airline from SEA to SLC
4 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Delta Air Linesmost reliable | 88% | 8 min | 0.5% | 4,711 |
| Alaska Airlines | 78% | 11 min | 1.3% | 2,708 |
| SkyWest Airlines | 78% | 12 min | 0.1% | 955 |
| Frontier Airlines | 76% | 15 min | 1.6% | 191 |
Monthly on-time trend
Best time to fly from SEA to SLC
Aim for departures around 5 a.m. (95% on-time); avoid 3 p.m. departures (72%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 84% | 10 min |
| Tuesdaybest | 86% | 8 min |
| Wednesday | 85% | 8 min |
| Thursday | 82% | 11 min |
| Friday | 81% | 10 min |
| Saturday | 84% | 9 min |
| Sunday | 82% | 11 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft39%
- Airline operations46%
- National airspace system12%
- Weather4%
Frequently asked questions
- How often are flights from SEA to SLC delayed?
- 17% of SEA–SLC flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-07 and 2026-07. The average arrival delay across completed flights was 10 minutes.
- Which airline is most reliable from SEA to SLC?
- Delta Air Lines has the best on-time record on this route at 88%, based on 4,711 flights. 4 airlines flew SEA–SLC frequently enough to compare in this period.
- What is the best time of day to fly from SEA to SLC?
- Departures around 5 a.m. have the best record (95% on-time), while departures around 3 p.m. have the worst (72%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from SEA to SLC?
- The scheduled SEA–SLC flight time averages 2h 6m over 689 miles. Actual arrival times vary — flights on this route land 15+ minutes late 17% of the time.
- How often are SEA to SLC flights cancelled?
- 0.7% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, at or below the national rate of 1.6%.
- What is the worst month to fly from SEA to SLC?
- July 2024 was the roughest month in this dataset, with only 75% of arrivals on time. The best was April 2026 at 92%. If your dates are flexible, that 17-point gap is worth planning around.
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Based on 8,565 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.