Air travel

How often are flights at Chicago (ORD) late?

In the 12 months through August 2026, 27.0% of flights leaving Chicago (ORD) left 15 or more minutes late, the 9th most of the 102 U.S. airports with at least 10,000 departures, against 22.9% of all U.S. flights. Airlines cancelled 2.8% of its scheduled departures (1.9% nationwide), the 15th most of the 102. Its worst month was December 2025, when 35.4% left late. Flights scheduled to leave in the 7 p.m. hour were late most often (39.6%), and those in the 6 a.m. hour least often (11.0%).

Left 15+ minutes late

27.0%

The 9th most of 102 airports

Cancelled

2.8%

The 15th most of 102 airports

Worst month

December 2025

35.4% left late

Flights leaving Chicago (ORD) 15+ minutes late, each month

The interactive chart needs JavaScript. The numbers are in the tables below.

Flights leaving Chicago (ORD) 15+ minutes late, by scheduled departure hour

The interactive chart needs JavaScript. The numbers are in the tables below.

Hours are local time at Chicago. Delays build through the day as late planes make their next flights late too. Hours with fewer than about one flight a day are left out.

The numbers

Departures from Chicago (ORD) each month and each scheduled departure hour.

Flights leaving Chicago (ORD) by month
Month Scheduled Left late Cancelled
September 2025 28,867 21.4% 0.4%
October 2025 31,096 23.2% 0.2%
November 2025 28,703 24.6% 5.6%
December 2025 27,790 35.4% 2.5%
January 2026 25,131 29.5% 3.7%
February 2026 25,538 22.4% 1.1%
March 2026 31,373 31.1% 5.7%
April 2026 33,206 26.5% 3.5%
May 2026 33,733 23.3% 1.0%
June 2026 31,374 26.9% 3.2%
July 2026 33,010 28.3% 4.2%
August 2026 33,187 32.0% 2.3%
Flights leaving Chicago (ORD) by departure hour
Departure hour Scheduled Left late Cancelled
Before 6 a.m. 3,419 12.8% 2.6%
6 a.m. 13,442 11.0% 1.9%
7 a.m. 23,377 11.7% 1.6%
8 a.m. 30,588 17.2% 1.5%
9 a.m. 24,794 20.5% 1.4%
10 a.m. 25,958 23.0% 1.6%
11 a.m. 19,358 24.6% 1.9%
Noon 18,635 24.7% 2.2%
1 p.m. 22,878 25.6% 2.3%
2 p.m. 23,534 27.9% 2.3%
3 p.m. 20,143 31.1% 3.2%
4 p.m. 22,245 31.9% 3.7%
5 p.m. 19,683 34.9% 4.2%
6 p.m. 23,622 35.1% 3.1%
7 p.m. 23,469 39.6% 3.8%
8 p.m. 20,373 38.9% 4.3%
9 p.m. 17,837 36.2% 4.8%
10 p.m. 8,362 36.6% 7.0%
11 p.m. 1,291 36.8% 9.7%

Source and notes

U.S. Bureau of Transportation Statistics, Airline On-Time Performance (Reporting Carrier On-Time Performance, 1987–present) (Public domain (U.S. government work)). Data from September 2025 through August 2026.

These are domestic flights of the large U.S. airlines that report to the Bureau of Transportation Statistics, including the regional airlines that fly for them. A flight is late when it leaves its gate 15 or more minutes after its scheduled time, out of the flights that left; cancellations are out of the flights scheduled. BTS posts each month about two months after it ends, and this page moves on a month when it does.