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

St. Louis, MO (STL) to Denver, CO (DEN) flight delay odds

74.4% of 3,655 official scheduled STL-to-DEN flights arrived on time; 16.2% arrived at least 30 minutes late and 0.4% 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
74.4%arrived on time
16.2%30+ min late
0.4%cancelled
3,655scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late9.2%all scheduled flights
120+ minutes late4.1%all scheduled flights
Diverted0.3%did not reach as scheduled
Average arrival+12.0 mincompleted flights

Which departure time was most reliable for STL to DEN?

Among qualifying STL-to-DEN departure window results, Early morning had the highest on-time rate: 88.4% of 992 flights. Night was lowest at 59.2% across 147 flights.

Departure windowFlightsOn time30+ minCancelled
Early morning99288.4%5.0%0.6%
Late morning49283.1%10.0%0.0%
Afternoon1,21369.8%18.8%0.4%
Evening81161.4%28.2%0.4%
Night14759.2%24.5%0.7%

Which weekday was most reliable for STL to DEN?

Among qualifying STL-to-DEN weekday results, Tuesday had the highest on-time rate: 79.2% of 499 flights. Monday was lowest at 70.1% across 552 flights.

DayFlightsOn time30+ minCancelled
Monday55270.1%19.9%0.7%
Tuesday49979.2%12.2%0.6%
Wednesday52778.7%14.6%0.0%
Thursday52471.8%17.7%0.6%
Friday56073.6%17.3%0.4%
Saturday44674.0%15.5%0.2%
Sunday54773.7%15.5%0.4%

Which airline was most reliable for STL to DEN?

Among qualifying STL-to-DEN airline results, SkyWest Airlines had the highest on-time rate: 85.9% of 142 flights. Southwest Airlines was lowest at 73.0% across 2,165 flights.

AirlineFlightsOn time30+ minCancelled
Southwest Airlines2,16573.0%16.7%0.2%
United Airlines1,07175.7%15.7%0.6%
Frontier Airlines27773.6%18.4%1.1%
SkyWest Airlines14285.9%7.7%0.7%

Which month was most reliable for STL to DEN?

Among qualifying STL-to-DEN month results, February 2026 had the highest on-time rate: 84.8% of 250 flights. July 2025 was lowest at 63.6% across 352 flights.

MonthFlightsOn time30+ minCancelled
July 202535263.6%25.3%1.4%
August 202533070.0%21.8%0.0%
September 202532677.6%12.9%0.0%
October 202533480.2%9.6%0.0%
November 202527581.8%12.0%0.4%
December 202526668.8%21.1%0.0%
January 202625182.9%7.6%0.8%
February 202625084.8%10.0%0.0%
March 202631772.9%15.8%0.3%
April 202628679.0%11.5%0.7%
May 202631071.6%18.4%0.3%
June 202635865.6%23.5%0.8%

What drove STL to DEN delay minutes?

Late aircraft was the largest recorded STL-to-DEN delay category, accounting for 39.7% of 63,999 BTS-attributed delay minutes during July 2025–June 2026.

Airline24.0%
Late aircraft39.7%
National airspace33.1%
Weather3.2%
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.