SLC to SEA flight delays & on-time performance
Nonstop flights from Salt Lake City International Airport to Seattle–Tacoma International Airport · 689 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at SLC or SEA right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Salt Lake City (SLC) to Seattle (SEA) arrived on time 80% of the time in Aug 2025 – Jul 2026, better than the 78% national average.
- 0.9% were cancelled, and 5% arrived an hour or more late.
- Delta Air Lines was the most punctual airline here (83% on time); SkyWest Airlines was the least (77%).
- Departures scheduled around 7am did best (92% on time); around 9am did worst (57%).
- Tuesday was the most reliable day to fly (84% on time) and Sunday the least (78%).
- The largest source of delay minutes was airline (crew, maintenance, cleaning, fueling) (39%).
Which airline is most on time from SLC to SEA?
Ranked by on-time arrival rate. Regional airlines fly under their partner's brand (e.g. SkyWest for Delta Connection or United Express).
| Airline | On time | Cancelled | Avg delay | 1 hr+ late | Flights |
|---|---|---|---|---|---|
| Delta Air Lines | 83% | 0.5% | 10 min | 4.6% | 2,230 |
| Alaska Airlines | 77% | 1.6% | 12 min | 4.4% | 1,417 |
| SkyWest AirlinesRegional airline operating flights for United Express, Delta Connection, American Eagle and Alaska. | 77% | 0.0% | 18 min | 6.0% | 388 |
| Frontier Airlines | 68% | 3.3% | 21 min | 11.5% | 90 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 6am94%111 flights
- 7am92%570 flights
- 8am92%53 flights
- 9am57%230 flights
- 11am87%636 flights
- 12pm79%131 flights
- 1pm83%372 flights
- 2pm92%75 flights
- 3pm75%631 flights
- 4pm69%99 flights
- 5pm81%340 flights
- 6pm72%102 flights
- 7pm76%115 flights
- 8pm61%303 flights
- 9pm66%105 flights
- 10pm91%208 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday78%0.9% cancelled
- Tuesday84%0.2% cancelled
- Wednesday83%0.4% cancelled
- Thursday78%1.1% cancelled
- Friday79%1.6% cancelled
- Saturday82%1.2% cancelled
- Sunday78%0.8% cancelled
On-time trend by month
Why flights are late
Share of delay minutes by cause, as reported by airlines to the DOT.
- Airline (crew, maintenance, cleaning, fueling)39%
- Late-arriving aircraft34%
- Air traffic control & airport congestion22%
- Extreme weather5%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
- Airline (crew, maintenance, cleaning, fueling)51%
- Extreme weather30%
- Air traffic control & airport congestion19%
- Security0%
SLC to SEA: common questions
- How often are SLC to SEA flights on time?
- 80% of flights arrived less than 15 minutes late in Aug 2025 – Jul 2026, compared with 78% for all US flights.
- How often are flights from Salt Lake City to Seattle cancelled?
- 0.9% of scheduled flights were cancelled (37 of 4,125).
- How long are typical delays?
- Across all flights the average arrival delay was 12 min (early arrivals count as zero). Flights that were late arrived 53 min behind schedule on average, and 4.8% of flights were an hour or more late.
- How long is taxi time at SLC?
- Flights on this route spent 20 min taxiing from the gate to takeoff on average.
Related routes
Return trip: SEA to SLC — 84% on time
More flights from Salt Lake City
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: SLC → SEA, nonstop flights by US airlines that report to the DOT. How we calculate this.