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

St. Louis, MO (STL) to San Diego, CA (SAN) flight delay odds

Historically, 74.5% of scheduled reportable flights on this direction arrived on time in July 2025–June 2026. The sample includes 474 flights.

HISTORICAL ROUTE SIGNALGenerally reliable
74.5%arrived on time
14.8%30+ min late
0.2%cancelled
474scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late5.3%all scheduled flights
120+ minutes late1.3%all scheduled flights
Diverted0.2%did not reach as scheduled
Average arrival+6.6 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 morning12885.9%5.5%0.8%
Late morning13984.9%8.6%0.0%
Afternoon13667.6%16.2%0.0%
Evening6648.5%37.9%0.0%

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
Monday6368.3%15.9%1.6%
Tuesday6083.3%10.0%0.0%
Wednesday5766.7%12.3%0.0%
Thursday6275.8%9.7%0.0%
Friday6876.5%10.3%0.0%
Saturday7979.7%16.5%0.0%
Sunday8570.6%24.7%0.0%

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 Airlines47474.5%14.8%0.2%

Monthly trend

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

MonthFlightsOn time30+ minCancelled
July 20253959.0%25.6%0.0%
August 20253663.9%22.2%0.0%
September 20253476.5%17.6%0.0%
October 20255771.9%17.5%0.0%
November 20254877.1%14.6%0.0%
December 20254665.2%21.7%0.0%
January 20263585.7%8.6%0.0%
February 20263577.1%5.7%0.0%
March 20263686.1%8.3%2.8%
April 20263491.2%5.9%0.0%
May 20263688.9%0.0%0.0%
June 20263857.9%23.7%0.0%

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.

Airline25.5%
Late aircraft45.6%
National airspace21.6%
Weather7.3%
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.