OnTimeStats

Historical on-time performance

St. Louis to Philadelphia

813 miData through May 2026Source: US DOT · BTS

Flights on STL–PHL arrive on time 77% of the time over the last 12 months.

On-time rate77%arrived within 15 min
p90 delay45 min1 in 10 flights is worse (tail risk)
Cancelled0.8%of scheduled flights

based on 1,308 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

Too close to call — no single carrier is clearly more on-time here.

  • PSA Airlines
    On-time86%
    Medianon time
    p90on time
    Cancel8.3%
    Flights36
  • American Airlines
    On-time77%
    Medianon time
    p9060 min
    Cancel1.0%
    Flights577
  • Southwest Airlines
    On-time76%
    Medianon time
    p9040 min
    Cancel0.3%
    Flights695

Why flights run late

Delay causes

  • Airline39%
  • Weather2%
  • Air traffic (NAS)8%
  • Late aircraft50%
  • Security0%

Most delay minutes here are attributed to Late aircraft.

When flights don't go

Why flights were cancelled

  • Airline0%
  • Weather91%
  • Air traffic (NAS)9%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 11 cancellations with a reported cause (BTS reports causes from June 2003).

Over time

On-time trend

By season

On-time rate by month

When to fly

Best time to fly STL → PHL

All airlines · rolling 36 months (2023-06 .. 2026-05).

Best time of day

Mornings are the most reliable time of day to fly this route — 88% on time.

  • Mornings88% on time · p90 15 min · 2,043 flights
  • Middays80% on time · p90 35 min · 754 flights
  • Evenings68% on time · p90 50 min · 651 flights
  • Afternoons67% on time · p90 60 min · 758 flights
  • Overnights59% on time · p90 75 min · 274 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 76% to 82% on time.

  • Wednesdays82% on time · p90 25 min · 631 flights
  • Saturdays81% on time · p90 30 min · 507 flights
  • Tuesdays80% on time · p90 35 min · 631 flights
  • Thursdays78% on time · p90 40 min · 662 flights
  • Mondays76% on time · p90 40 min · 688 flights
  • Fridays76% on time · p90 45 min · 690 flights
  • Sundays76% on time · p90 40 min · 671 flights

Keep exploring

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.