BTS DATA COMPLETE THROUGH JUNE 2026HISTORICAL ODDS · NOT LIVE FLIGHT STATUS
DelayOddsKnow the route before you book
SLC→SEA

Salt Lake City, UT (SLC) to Seattle, WA (SEA) flight delay odds

79.3% of 4,108 official scheduled SLC-to-SEA flights arrived on time; 10.5% arrived at least 30 minutes late and 1.0% were cancelled during July 2025–June 2026.

Source: U.S. Bureau of Transportation Statistics · Reporting window: July 2025–June 2026 · Updated September 16, 2026

HISTORICAL ROUTE SIGNALGenerally reliable
79.3%arrived on time
10.5%30+ min late
1.0%cancelled
4,108scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late4.6%all scheduled flights
120+ minutes late1.7%all scheduled flights
Diverted0.1%did not reach as scheduled
Average arrival+2.6 mincompleted flights

Which departure time was most reliable for SLC to SEA?

Among qualifying SLC-to-SEA departure window results, Early morning had the highest on-time rate: 91.3% of 755 flights. Evening was lowest at 72.9% across 835 flights.

Departure windowFlightsOn time30+ minCancelled
Early morning75591.3%3.8%0.5%
Late morning85677.8%10.4%0.7%
Afternoon1,30276.9%12.6%1.0%
Evening83572.9%14.5%1.9%
Night36081.4%7.8%0.3%

Which weekday was most reliable for SLC to SEA?

Among qualifying SLC-to-SEA weekday results, Tuesday had the highest on-time rate: 82.9% of 550 flights. Friday was lowest at 77.1% across 629 flights.

DayFlightsOn time30+ minCancelled
Monday64477.6%11.5%1.1%
Tuesday55082.9%8.5%0.2%
Wednesday54282.3%10.3%0.4%
Thursday61077.2%11.0%1.3%
Friday62977.1%10.8%1.6%
Saturday51481.3%8.6%1.4%
Sunday61977.9%12.1%0.8%

Which airline was most reliable for SLC to SEA?

Among qualifying SLC-to-SEA airline results, Delta Air Lines had the highest on-time rate: 82.8% of 2,222 flights. Frontier Airlines was lowest at 67.3% across 98 flights.

AirlineFlightsOn time30+ minCancelled
Delta Air Lines2,22282.8%9.4%0.5%
Alaska Airlines1,36975.3%11.6%1.8%
SkyWest Airlines41976.6%11.2%0.0%
Frontier Airlines9867.3%17.3%3.1%

Which month was most reliable for SLC to SEA?

Among qualifying SLC-to-SEA month results, April 2026 had the highest on-time rate: 88.9% of 315 flights. December 2025 was lowest at 70.0% across 303 flights.

MonthFlightsOn time30+ minCancelled
July 202539473.4%12.9%1.0%
August 202540971.1%15.4%1.2%
September 202539881.7%9.3%0.3%
October 202536778.5%10.6%1.4%
November 202529980.6%8.4%3.0%
December 202530370.0%16.5%0.3%
January 202629983.6%7.4%0.3%
February 202629387.0%6.8%0.3%
March 202633581.5%9.0%3.3%
April 202631588.9%4.4%0.3%
May 202633882.5%9.5%0.3%
June 202635876.8%13.4%0.0%

What drove SLC to SEA delay minutes?

Airline was the largest recorded SLC-to-SEA delay category, accounting for 40.1% of 43,041 BTS-attributed delay minutes during July 2025–June 2026.

Airline40.1%
Late aircraft32.7%
National airspace21.6%
Weather5.6%
Security0.1%
This is historical evidence, not a forecast.

Weather, schedules and operations change. For a trip you have already booked, use the airline or airport for live status.