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

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

Historically, 78.3% of scheduled reportable flights on this direction arrived on time in July 2025–June 2026. The sample includes 1,587 flights.

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

When is this route most reliable?

The same route can behave differently through the day. These are scheduled departure windows, not actual departure times. Small time windows with fewer than 40 flights are withheld.

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%

Weekday comparison

Day-of-week results use at least 30 scheduled flights per row. Look for broad patterns, not tiny percentage differences.

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%

Airline comparison

Marketing-carrier results make codeshare flights easier to compare as travelers buy them. Dedicated route-airline reports require at least 160 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%

Monthly trend

Month-by-month results show whether a twelve-month average hides an unusual period.

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 reported delay minutes?

BTS cause minutes are reported for qualifying delayed flights. These shares describe recorded delay minutes—not the chance that a particular cause will affect your next flight.

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.