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

San Francisco, CA (SFO) to Chicago, IL (MDW) flight delay odds

Historically, 73.4% of scheduled reportable flights on this direction arrived on time in July 2025–June 2026. The sample includes 455 flights.

HISTORICAL ROUTE SIGNALGenerally reliable
73.4%arrived on time
13.4%30+ min late
1.3%cancelled
455scheduled 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 late0.4%all scheduled flights
Diverted0.9%did not reach as scheduled
Average arrival+5.5 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 morning27986.0%4.3%1.8%
Late morning5162.7%17.6%0.0%
Night11851.7%30.5%0.8%

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
Monday6675.8%12.1%1.5%
Tuesday6283.9%6.5%0.0%
Wednesday5978.0%11.9%0.0%
Thursday6674.2%13.6%3.0%
Friday6669.7%12.1%1.5%
Saturday6969.6%11.6%1.4%
Sunday6764.2%25.4%1.5%

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 Airlines45573.4%13.4%1.3%

Monthly trend

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

MonthFlightsOn time30+ minCancelled
July 20253177.4%6.5%3.2%
August 20253174.2%12.9%0.0%
September 20253066.7%10.0%0.0%
October 20253190.3%3.2%0.0%
November 20253083.3%6.7%0.0%
December 20253183.9%6.5%0.0%
January 20261464.3%21.4%0.0%
February 20261989.5%10.5%0.0%
March 20265678.6%5.4%5.4%
April 20266070.0%20.0%3.3%
May 20266262.9%19.4%0.0%
June 20266061.7%25.0%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.

Airline17.7%
Late aircraft60.2%
National airspace21.2%
Weather0.0%
Security0.9%
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.