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

Chicago, IL (MDW) to Ontario, CA (ONT) flight delay odds

69.2% of 360 official scheduled MDW-to-ONT flights arrived on time; 18.6% arrived at least 30 minutes late and 1.1% 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 SIGNALVariable
69.2%arrived on time
18.6%30+ min late
1.1%cancelled
360scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late8.6%all scheduled flights
120+ minutes late2.8%all scheduled flights
Diverted0.0%did not reach as scheduled
Average arrival+13.9 mincompleted flights

Which departure time was most reliable for MDW to ONT?

Among qualifying MDW-to-ONT departure window results, Early morning had the highest on-time rate: 84.1% of 113 flights. Evening was lowest at 62.1% across 58 flights.

Departure windowFlightsOn time30+ minCancelled
Early morning11384.1%7.1%0.9%
Late morning10367.0%23.3%1.0%
Afternoon6564.6%20.0%0.0%
Evening5862.1%24.1%1.7%

Which weekday was most reliable for MDW to ONT?

Among qualifying MDW-to-ONT weekday results, Wednesday had the highest on-time rate: 76.9% of 52 flights. Sunday was lowest at 57.7% across 52 flights.

DayFlightsOn time30+ minCancelled
Monday5269.2%19.2%3.8%
Tuesday5371.7%22.6%0.0%
Wednesday5276.9%17.3%0.0%
Thursday5271.2%17.3%0.0%
Friday5271.2%11.5%0.0%
Saturday4766.0%14.9%2.1%
Sunday5257.7%26.9%1.9%

Which airline was most reliable for MDW to ONT?

Only Southwest Airlines met the MDW-to-ONT airline threshold: 69.2% of 360 scheduled flights arrived on time during July 2025–June 2026.

AirlineFlightsOn time30+ minCancelled
Southwest Airlines36069.2%18.6%1.1%

Which month was most reliable for MDW to ONT?

Among qualifying MDW-to-ONT month results, November 2025 had the highest on-time rate: 90.0% of 30 flights. June 2026 was lowest at 46.7% across 30 flights.

MonthFlightsOn time30+ minCancelled
July 20253158.1%35.5%0.0%
August 20253167.7%16.1%3.2%
September 20253076.7%13.3%0.0%
October 20253174.2%9.7%0.0%
November 20253090.0%3.3%6.7%
December 20253164.5%25.8%0.0%
January 20262777.8%14.8%0.0%
February 20262788.9%3.7%0.0%
March 20263164.5%22.6%3.2%
April 20263073.3%10.0%0.0%
May 20263151.6%25.8%0.0%
June 20263046.7%40.0%0.0%

What drove MDW to ONT delay minutes?

Airline was the largest recorded MDW-to-ONT delay category, accounting for 41.9% of 6,261 BTS-attributed delay minutes during July 2025–June 2026.

Airline41.9%
Late aircraft40.3%
National airspace14.1%
Weather3.7%
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.