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

St. Louis, MO (STL) to Chicago, IL (ORD) flight delay odds

Historically, 68.7% of scheduled reportable flights on this direction arrived on time in July 2025–June 2026. The sample includes 3,070 flights.

HISTORICAL ROUTE SIGNALVariable
68.7%arrived on time
19.6%30+ min late
3.2%cancelled
3,070scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late11.6%all scheduled flights
120+ minutes late5.9%all scheduled flights
Diverted0.1%did not reach as scheduled
Average arrival+20.9 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 morning93079.1%13.1%2.2%
Late morning30275.5%18.2%1.7%
Afternoon1,05665.8%21.9%3.6%
Evening78057.6%25.0%4.6%

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
Monday45764.6%23.4%5.9%
Tuesday44172.3%16.3%1.8%
Wednesday43371.6%17.1%2.8%
Thursday45070.0%17.3%2.7%
Friday44966.8%19.8%3.6%
Saturday39072.1%17.4%2.8%
Sunday45064.4%25.6%2.9%

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
SkyWest Airlines83659.7%27.2%4.9%
Envoy Air72872.7%17.3%2.6%
American Airlines53378.6%13.7%2.4%
United Airlines52567.4%18.3%1.5%
Republic Airways44869.0%18.1%4.0%

Monthly trend

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

MonthFlightsOn time30+ minCancelled
July 202528960.2%26.0%1.7%
August 202525566.3%18.4%3.9%
September 202523980.3%12.1%0.8%
October 202527470.4%17.9%0.0%
November 202524164.7%22.4%4.6%
December 202524060.8%30.0%2.9%
January 202615667.9%22.4%4.5%
February 202618583.2%9.7%0.5%
March 202627160.1%22.9%8.1%
April 202629467.7%19.0%5.1%
May 202632278.9%13.0%1.9%
June 202630467.1%21.1%4.3%

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.

Airline28.8%
Late aircraft29.3%
National airspace32.3%
Weather9.5%
Security0.1%
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.