OnTimeStats

Historical on-time performance

STLDEN

St. Louis to Denver

770 miData through Dec 2025Source: US DOT · BTS

Flights on STL–DEN arrive on time 73% of the time over the last 12 months.

On-time rate73%arrived within 15 min
Median delayon timetypical arrival
p90 delay60 min1 in 10 flights is worsetail risk
Cancelled0.7%of scheduled flights

based on 3,417 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • Frontier Airlinesbest
    On-time87%
    Medianon time
    p9020 min
    Cancel1.1%
    Flights91
  • SkyWest Airlines
    On-time85%
    Medianon time
    p9020 min
    Cancel0.0%
    Flights122
  • Southwest Airlines
    On-time74%
    Medianon time
    p9060 min
    Cancel0.8%
    Flights2,128
  • United Airlines
    On-time71%
    Medianon time
    p9070 min
    Cancel0.6%
    Flights1,076

Why flights run late

Delay causes

  • Airline22%
  • Weather4%
  • Air traffic (NAS)42%
  • Late aircraft32%
  • Security0%

Most delay minutes here are attributed to Air traffic (NAS).

Over time

On-time trend

By season

On-time rate by month

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Related pages

Methodology

A flight is on time when it arrives within 15 minutes of schedule — the US DOT / BTS standard. Median and p90(the “1-in-10 bad day”) are read from the full arrival-delay distribution, never averaged across periods.

Figures cover a carrier’s own BTS-coded flights. Cells below ~200 flights are flagged as limited data. All numbers are pre-computed from public BTS On-Time Performance data.