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

Denver, CO (DEN) to Seattle, WA (SEA) flight delay odds

73.4% of 6,309 official scheduled DEN-to-SEA flights arrived on time; 16.0% arrived at least 30 minutes late and 0.8% 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
73.4%arrived on time
16.0%30+ min late
0.8%cancelled
6,309scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late7.3%all scheduled flights
120+ minutes late2.5%all scheduled flights
Diverted0.0%did not reach as scheduled
Average arrival+9.0 mincompleted flights

Which departure time was most reliable for DEN to SEA?

Among qualifying DEN-to-SEA departure window results, Early morning had the highest on-time rate: 85.6% of 1,727 flights. Night was lowest at 58.1% across 482 flights.

Departure windowFlightsOn time30+ minCancelled
Early morning1,72785.6%6.8%0.6%
Late morning72978.6%12.5%0.5%
Afternoon1,75873.8%15.1%0.8%
Evening1,61362.0%24.6%0.7%
Night48258.1%28.0%1.7%

Which weekday was most reliable for DEN to SEA?

Among qualifying DEN-to-SEA weekday results, Saturday had the highest on-time rate: 76.2% of 835 flights. Thursday was lowest at 69.2% across 934 flights.

DayFlightsOn time30+ minCancelled
Monday93573.5%14.7%0.6%
Tuesday86075.8%14.4%0.3%
Wednesday86975.9%13.9%0.3%
Thursday93469.2%18.0%1.0%
Friday93470.4%17.2%1.7%
Saturday83576.2%16.3%0.7%
Sunday94273.2%17.0%0.5%

Which airline was most reliable for DEN to SEA?

Among qualifying DEN-to-SEA airline results, United Airlines had the highest on-time rate: 79.5% of 1,903 flights. Southwest Airlines was lowest at 61.4% across 1,341 flights.

AirlineFlightsOn time30+ minCancelled
United Airlines1,90379.5%12.1%0.6%
Alaska Airlines1,55873.0%15.6%1.0%
Southwest Airlines1,34161.4%23.6%0.3%
Delta Air Lines86878.5%13.1%0.9%
Frontier Airlines41973.5%16.0%1.9%
SkyWest Airlines22075.5%16.4%0.5%

Which month was most reliable for DEN to SEA?

Among qualifying DEN-to-SEA month results, April 2026 had the highest on-time rate: 83.8% of 469 flights. December 2025 was lowest at 58.8% across 468 flights.

MonthFlightsOn time30+ minCancelled
July 202567062.4%24.6%1.6%
August 202564564.8%22.2%0.6%
September 202557578.6%13.0%0.0%
October 202555279.2%12.0%0.7%
November 202546482.5%8.6%1.7%
December 202546858.8%24.1%0.9%
January 202643083.0%8.8%0.0%
February 202640183.3%9.7%0.0%
March 202645567.7%18.9%1.8%
April 202646983.8%8.1%0.2%
May 202654676.6%13.2%0.0%
June 202663468.8%20.8%1.3%

What drove DEN to SEA delay minutes?

Late aircraft was the largest recorded DEN-to-SEA delay category, accounting for 44.5% of 93,659 BTS-attributed delay minutes during July 2025–June 2026.

Airline34.9%
Late aircraft44.5%
National airspace17.9%
Weather2.5%
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.