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

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

76.7% of 6,317 official scheduled SEA-to-DEN flights arrived on time; 13.4% arrived at least 30 minutes late and 0.9% 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
76.7%arrived on time
13.4%30+ min late
0.9%cancelled
6,317scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late6.3%all scheduled flights
120+ minutes late2.2%all scheduled flights
Diverted0.5%did not reach as scheduled
Average arrival+5.2 mincompleted flights

Which departure time was most reliable for SEA to DEN?

Among qualifying SEA-to-DEN departure window results, Early morning had the highest on-time rate: 87.8% of 2,045 flights. Afternoon was lowest at 68.0% across 2,384 flights.

Departure windowFlightsOn time30+ minCancelled
Early morning2,04587.8%5.7%0.8%
Late morning62280.2%9.5%0.6%
Afternoon2,38468.0%19.3%1.0%
Evening1,26473.6%16.6%0.7%

Which weekday was most reliable for SEA to DEN?

Among qualifying SEA-to-DEN weekday results, Saturday had the highest on-time rate: 81.7% of 836 flights. Friday was lowest at 73.1% across 938 flights.

DayFlightsOn time30+ minCancelled
Monday93377.4%12.5%1.0%
Tuesday86276.8%13.3%0.5%
Wednesday86980.2%11.5%0.2%
Thursday93574.3%13.6%1.4%
Friday93873.1%16.4%1.5%
Saturday83681.7%10.5%0.6%
Sunday94474.5%15.3%0.7%

Which airline was most reliable for SEA to DEN?

Among qualifying SEA-to-DEN airline results, United Airlines had the highest on-time rate: 86.1% of 1,905 flights. Southwest Airlines was lowest at 68.0% across 1,345 flights.

AirlineFlightsOn time30+ minCancelled
United Airlines1,90586.1%7.7%0.8%
Alaska Airlines1,55875.1%14.1%0.8%
Southwest Airlines1,34568.0%18.0%0.6%
Delta Air Lines86972.3%17.3%0.9%
Frontier Airlines41973.5%15.3%1.9%
SkyWest Airlines22184.6%10.4%0.5%

Which month was most reliable for SEA to DEN?

Among qualifying SEA-to-DEN month results, April 2026 had the highest on-time rate: 87.4% of 470 flights. July 2025 was lowest at 59.1% across 670 flights.

MonthFlightsOn time30+ minCancelled
July 202567059.1%25.2%1.2%
August 202564464.4%21.1%0.8%
September 202557475.6%13.2%0.0%
October 202555782.6%8.8%0.7%
November 202546683.9%8.8%2.6%
December 202546879.3%11.5%0.6%
January 202642987.2%5.6%0.2%
February 202640385.1%9.4%0.0%
March 202645577.1%13.8%2.6%
April 202647087.4%6.4%0.2%
May 202654682.4%9.5%0.2%
June 202663571.2%17.8%1.1%

What drove SEA to DEN delay minutes?

Late aircraft was the largest recorded SEA-to-DEN delay category, accounting for 34.1% of 79,952 BTS-attributed delay minutes during July 2025–June 2026.

Airline30.7%
Late aircraft34.1%
National airspace30.9%
Weather4.3%
Security0.0%
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.