PlainFlights

Airport · IAH · Houston, Texas

Houston, TX

Houston, TX posts below-median on-time performance among the 382 tracked U.S. airports, as one of the busiest U.S. airports. According to the U.S. DOT Bureau of Transportation Statistics, drawn from 1,404,392 flights (2020–2025); its biggest delay driver is carrier.

Data updated 2026-06-13

81.6%
On-time
Top 71%
on-time, US airports
80 min
Delay when late
1.13%
Cancelled

Key Performance Metrics

Total Flights

1,404,392

Best Month

Sep 92.8%

Worst Month

Jul 86.4%

Delayed

258,419

Cancelled

15,858

IAH on-time rate vs. the national average

Ahead of the U.S. average across all 382 tracked airports.

0%100%U.S. average79%81.6%

Where IAH sits among all 382 tracked airports

IAH's 81.6% on-time rate falls in the 80-85% band, the 192-airport band it shares.

National on-time-rate distribution

airports

What this shows IAH is marked in the 80-85% band.

Delay Cause Breakdown

Top delay cause: Carrier. Total delay minutes: 9,961,952.

Late Aircraft 34.9% (3,475,885 min)
Carrier 38.4% (3,821,797 min)
NAS (National Aviation System) 18.1% (1,806,413 min)
Weather 8.6% (852,957 min)
Security 0.0% (4,900 min)

IAH - seasonal on-time pattern

Best: September (92.8%) · worst: July (86.4%)

86%88%90%92%94% JanFebMarAprMayJunJulAugSepOctNovDec 89.9%

Seasonal Performance Patterns

Monthly averages across all years of data. Best month: September (92.8% on-time). Most delays: July (86.4% on-time).

Month Avg Flights Avg Delayed Avg Cancelled On-Time %
December 19,389 3,736 133 89.9%
November 19,245 2,842 50 92.3%
October 20,374 2,922 66 92.6%
September 19,265 2,648 80 92.8%
August 20,355 4,060 215 89.5%
July 20,178 5,238 247 86.4%
June 18,331 4,615 163 86.6%
May 18,534 4,043 157 88.3%
April 17,780 2,966 405 91.2%
March 21,723 3,534 546 91.5%
February 18,914 2,948 251 92.2%
January 19,979 3,517 333 91%

Year-Over-Year Performance

Annual flight volume and on-time trends at IAH.

IAH - on-time rate by year

2020–2025, year-over-year trend.

85%90%95%100% 202020212022202320242025 95.8% 88.7% ▼ -7.4%
Year Flights Delayed Cancelled On-Time %
2025 234,519 26,561 1,513 88.7%
2024 231,901 27,735 2,354 88%
2023 223,791 25,159 1,200 88.8%
2022 251,715 24,478 2,414 90.3%
2021 258,020 22,646 2,720 91.2%
2020 204,446 8,675 5,657 95.8%

Cancellation & Diversion Analysis

Flight disruption statistics for Houston, TX.

Cancellation Rate

1.13%

15,858 of 1,404,392 flights

Diversion Rate

0.12%

1,741 of 1,404,392 flights

Delay Rate

18.4%

258,419 of 1,404,392 flights

Monthly Performance

Recent 24 months of flight data.

Period Flights Dep Delayed Arr Delayed Cancelled Diverted
Dec 2025 19,942 2,100 2,024 60 20
Nov 2025 20,046 2,025 1,905 106 14
Oct 2025 20,496 1,766 1,844 31 19
Sep 2025 18,982 1,333 1,224 19 12
Aug 2025 19,780 2,480 2,287 86 31
Jul 2025 20,625 3,170 2,737 179 61
Jun 2025 20,010 3,354 3,004 232 56
May 2025 20,485 2,800 2,460 134 33
Apr 2025 19,015 1,860 1,675 46 22
Mar 2025 19,700 2,037 1,614 65 36
Feb 2025 16,931 1,682 1,516 37 12
Jan 2025 18,507 1,954 1,807 518 26
Dec 2024 19,151 2,306 1,997 113 30
Nov 2024 19,156 1,488 1,321 21 11
Oct 2024 20,455 1,463 1,179 52 12
Sep 2024 19,013 1,577 1,319 56 16
Aug 2024 20,560 2,525 2,078 151 43
Jul 2024 20,771 4,033 3,377 800 39
Jun 2024 20,054 3,098 2,434 134 47
May 2024 20,250 3,684 3,135 340 39
Apr 2024 18,575 2,000 1,667 43 27
Mar 2024 19,114 2,218 1,846 61 27
Feb 2024 16,930 1,193 1,028 21 15
Jan 2024 17,872 2,150 1,974 562 32

Top Routes from IAH

Busiest routes to and from Houston, TX.

Route Flights On-Time Distance
IAH (Houston) → DFW (Dallas/Fort Worth) 30,197 76.6% 224 mi
DFW (Dallas/Fort Worth) → IAH (Houston) 30,188 76.3% 224 mi
IAH (Houston) → LAX (Los Angeles) 28,113 83.4% 1,379 mi
LAX (Los Angeles) → IAH (Houston) 28,102 86.2% 1,379 mi
IAH (Houston) → DEN (Denver) 27,947 80% 862 mi
IAH (Houston) → ORD (Chicago) 27,946 81% 925 mi
DEN (Denver) → IAH (Houston) 27,936 76.7% 862 mi
ORD (Chicago) → IAH (Houston) 27,881 80.7% 925 mi
ATL (Atlanta) → IAH (Houston) 26,083 79.5% 689 mi
IAH (Houston) → ATL (Atlanta) 26,071 80.8% 689 mi
LAS (Las Vegas) → IAH (Houston) 21,832 82.2% 1,222 mi
IAH (Houston) → LAS (Las Vegas) 21,825 80.3% 1,222 mi
LGA (New York) → IAH (Houston) 21,492 82% 1,416 mi
IAH (Houston) → LGA (New York) 21,489 79.3% 1,416 mi
MCO (Orlando) → IAH (Houston) 20,518 79.5% 854 mi
IAH (Houston) → MCO (Orlando) 20,515 78.4% 854 mi
EWR (Newark) → IAH (Houston) 19,919 78.5% 1,400 mi
IAH (Houston) → EWR (Newark) 19,906 76.6% 1,400 mi
MSY (New Orleans) → IAH (Houston) 18,136 84.4% 305 mi
IAH (Houston) → MSY (New Orleans) 18,111 81.6% 305 mi

Airports With a Similar On-Time Rate

Other U.S. airports nationwide whose on-time rate is closest to Houston, TX's 81.6%.

Raleigh/Durham, NC

81.6% on-time 616,332 flights

Norfolk, VA

81.6% on-time 231,501 flights

Richmond, VA

81.6% on-time 203,348 flights

Sioux Falls, SD

81.6% on-time 83,262 flights

Birmingham, AL

81.5% on-time 178,467 flights

Syracuse, NY

81.5% on-time 131,663 flights

Other Airports in Texas

Compare performance with other Texas airports.

DFW 78.5%

Dallas/Fort Worth, TX

Dallas/Fort Worth · 3,395,134 flights
AUS 79.3%

Austin, TX

Austin · 909,441 flights
DAL 77.6%

Dallas, TX

Dallas · 791,209 flights
HOU 79.4%

Houston, TX

Houston · 618,821 flights
SAT 81.7%

San Antonio, TX

San Antonio · 419,736 flights
ELP 81.4%

El Paso, TX

El Paso · 186,225 flights
MAF 82.9%

Midland/Odessa, TX

Midland/Odessa · 100,719 flights
LBB 82%

Lubbock, TX

Lubbock · 69,433 flights

Keep exploring

More flight data around Houston, TX.

Texas flight data

Statewide on-time and delay aggregates, plus every reporting airport in Texas.

View TX data →

Airport rankings

See where IAH sits among U.S. airports on on-time rate and average delay.

Best on-time airports →

Compare airports

Put IAH head-to-head with another airport on delays and reliability.

Open comparison tool →

What the Data Says About IAH

Houston, TX in Houston, Texas handled 1,404,392 flights in the Bureau of Transportation Statistics dataset between 2020 and 2025, posting a 81.6% on-time departure rate. Of those flights, 258,419 experienced delays, 15,858 were cancelled, and 1,741 were diverted. The cancellation rate works out to 1.13%, the diversion rate to 0.12%, and the average delay when departures run late is 79.8 minutes. These figures are the baseline for comparing IAH against other airports in the same state and nationally.

Breaking down what drives delays at IAH, Carrier leads the pack. Carrier accounts for 38.4% of total delay minutes, followed by Late Aircraft at 34.9% and NAS (National Aviation System) at 18.1%. Weather contributes 8.6% of delay minutes at this airport, while security holds the smallest share at 0.0%. Travelers often overestimate the weather share; the BTS categorization shows late-arriving aircraft and carrier operations as the larger contributors.

Seasonally, September runs the cleanest at IAH with a 92.8% on-time rate, while July is the roughest at 86.4% - a 6-point swing between best and worst month. Volume peaks in March, when average flights hit 21,723. The busiest route connecting IAH is to DFW (Dallas/Fort Worth), with 30,197 flights at a 76.6% on-time rate. Combine these numbers - 81.6% on-time, 79.8-minute average delay, 1.13% cancellation rate, and you have a concrete picture of departure reliability at Houston, TX.

Frequently Asked Questions

What is the on-time performance rate at Houston, TX (IAH)? ▼
Houston, TX has an overall on-time departure rate of 81.6%. Out of 1,404,392 total flights tracked, 258,419 experienced delays and 15,858 were cancelled.
What is the most common cause of delays at IAH? ▼
The top delay cause at Houston, TX is Carrier. Carrier accounts for 38.4% of all delay minutes.
What is the average delay time at IAH? ▼
The average delay at Houston, TX is 79.8 minutes. This includes delays from carrier issues, weather, National Aviation System constraints, security, and late-arriving aircraft.
What is the best month to fly from IAH? ▼
Based on historical data, September has the best on-time performance at IAH with 92.8% of flights departing on time.
What is the worst month for delays at IAH? ▼
July tends to have the most delays at IAH, with an on-time rate of only 86.4%.
How many routes operate from IAH? ▼
Houston, TX serves at least 20 routes. The busiest route is IAH to DFW (Houston - Dallas/Fort Worth) with 30,197 flights.
What is the cancellation rate at IAH? ▼
Houston, TX has a cancellation rate of 1.13%, based on 15,858 cancelled flights out of 1,404,392 total flights tracked.

Flight Guides

Data-driven guides to help you understand airport and flight performance.

Best & Worst Airlines for On-Time Performance

Which carriers consistently outperform peers

Why Flights Get Cancelled

Cancellation causes broken down by data

How to Choose Reliable Flight Routes

Use delay data to pick flights that arrive on time

Explore PlainFlights

All Airports

Browse US airports
Airlines

Compare carrier performance
Routes

Flight route performance
Rankings

Best on-time airports
Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data (2020–2025). Statistics reflect cumulative performance across all available reporting periods. On-time rates exclude cancelled and diverted flights.

Read our methodology - how this data is sourced, computed, and verified.

Using IAH's data

An airport-level on-time rate is a starting point, not a guarantee for your specific flight.

  • Check the busiest route from IAH before you book a connection. See top routes
  • Travel in September rather than July if your dates are flexible. Seasonal patterns
  • Scores vary by airline and route within the same airport; check the specific carrier you're flying. Browse airlines

On-time rate reflects the BTS historical average across all reporting carriers at this airport, not any single flight or airline.

Related

All airports → | Rankings →
Data sourced from U.S. Department of Transportation Bureau of Transportation Statistics (BTS) On-Time Performance data. See our methodology for details. Retrieved and formatted by PlainFlights Editorial

Source: U.S. Bureau of Transportation Statistics (BTS) Airline on-time performance and operational reliability · 2025

Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. Airport figures are computed directly from BTS On-Time Performance data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.