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

St. Louis, MO (STL) to Philadelphia, PA (PHL) flight delay odds

78.3% of 1,587 official scheduled STL-to-PHL flights arrived on time; 13.6% arrived at least 30 minutes late and 1.4% 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
78.3%arrived on time
13.6%30+ min late
1.4%cancelled
1,587scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late7.7%all scheduled flights
120+ minutes late3.2%all scheduled flights
Diverted0.3%did not reach as scheduled
Average arrival+8.1 mincompleted flights

Which departure time was most reliable for STL to PHL?

Among qualifying STL-to-PHL departure window results, Early morning had the highest on-time rate: 89.0% of 546 flights. Evening was lowest at 64.7% across 343 flights.

Departure windowFlightsOn time30+ minCancelled
Early morning54689.0%5.7%2.2%
Late morning22385.7%11.7%0.4%
Afternoon45772.6%16.4%1.5%
Evening34364.7%23.0%0.6%

Which weekday was most reliable for STL to PHL?

Among qualifying STL-to-PHL weekday results, Wednesday had the highest on-time rate: 83.3% of 222 flights. Sunday was lowest at 70.3% across 246 flights.

DayFlightsOn time30+ minCancelled
Monday24575.9%16.3%2.4%
Tuesday22778.9%14.1%0.4%
Wednesday22283.3%8.1%0.9%
Thursday23781.0%11.4%1.7%
Friday23879.8%12.6%0.4%
Saturday17279.7%14.0%0.6%
Sunday24670.3%18.3%2.8%

Which airline was most reliable for STL to PHL?

Among qualifying STL-to-PHL airline results, Republic Airways had the highest on-time rate: 83.0% of 100 flights. Southwest Airlines was lowest at 75.7% across 724 flights.

AirlineFlightsOn time30+ minCancelled
Southwest Airlines72475.7%14.6%0.6%
American Airlines63080.2%13.2%1.1%
PSA Airlines13379.7%11.3%6.8%
Republic Airways10083.0%12.0%2.0%

Which month was most reliable for STL to PHL?

Among qualifying STL-to-PHL month results, February 2026 had the highest on-time rate: 85.7% of 84 flights. July 2025 was lowest at 63.7% across 135 flights.

MonthFlightsOn time30+ minCancelled
July 202513563.7%21.5%3.7%
August 202514278.9%10.6%0.0%
September 202513281.8%12.9%0.0%
October 202514781.6%10.9%0.0%
November 202516284.0%9.3%0.6%
December 202514877.7%15.5%0.7%
January 202610284.3%8.8%4.9%
February 20268485.7%4.8%8.3%
March 202611672.4%21.6%0.9%
April 202612985.3%9.3%0.8%
May 202614369.9%18.2%0.0%
June 202614776.9%17.0%0.7%

What drove STL to PHL delay minutes?

Late aircraft was the largest recorded STL-to-PHL delay category, accounting for 51.0% of 26,503 BTS-attributed delay minutes during July 2025–June 2026.

Airline35.4%
Late aircraft51.0%
National airspace9.1%
Weather4.5%
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.