How thunderstorms affects
flights at IAH.
George Bush Intercontinental (IAH) in Houston. Historical delay data, cancellation risk, airline performance, and what to do when thunderstorms hits. Season: May - Sep.
Thunderstorms Impact at IAH
Based on historical flight performance data during May - Sep
75%
On-time rate
during thunderstorms
1.8%
Cancellation
rate
81m
Avg delay
when late
-7%
On-time rate drop
vs off-peak months
9 precip days/month
During
May - Sep
What happens at IAH during thunderstorms
Summer thunderstorms cause ground stops, lightning-related ramp closures, and air traffic control delays. Convective weather is the leading cause of FAA ground delay programs and affects hub airports across the South and Midwest.
Historical impact
During May - Sep, IAH's on-time rate drops to 75% — compared to 82% during non-peak months. That's a 7-point drop, making thunderstorms the most significant weather disruption at this airport. Cancellations rise from 1.3% to 1.8% during peak thunderstorms months.
Typical recovery time
1-3 hours after cells pass. Ground stops lift quickly, but cascading delays from rerouted aircraft can persist into the evening.
Which airlines handle thunderstorms best at IAH?
All airlines are subject to the same runway closures and ground stops, but some handle disruption better than others — faster rebooking, better crew scheduling, and more de-icing capacity.
Best at IAH
Delta Air Lines
81% on-time · 79m avg delay
Most delayed
JetBlue Airways
66% on-time · 80m avg delay
Based on overall performance at IAH. Individual flight performance varies by route and time of day.
Tips for flying through IAH during thunderstorms
Fly before noon
Summer thunderstorms at IAH typically build in the afternoon. Morning flights have significantly better on-time rates during convective season.
Watch for ground stops on FAA.gov
The FAA posts ground delay programs in real time. If your departure airport has a GDP into your arrival airport, your flight will be delayed at the gate.
Don't panic at the gate
Thunderstorm delays are usually 1-3 hours. Unlike snow, once cells pass, operations resume quickly. Cancellations are rare unless storms persist past 8 PM.
Set up flight alerts
Gate changes and delay updates happen fast during convective weather. A free FlightCheck briefing tells you what to expect before you leave for the airport.
Get a free flight briefing for IAH
Weather risk, delay probability, and what to expect — delivered to your inbox before you fly.
Common questions
How does thunderstorms affect flights at IAH?
During thunderstorms season, IAH averages a 75% on-time rate with an average delay of 81 minutes when flights are late. The cancellation rate during peak months is 1.8%.
What months are worst for thunderstorms at IAH?
Thunderstorms at IAH peaks during May - Sep. These months show measurably higher delay and cancellation rates compared to the rest of the year.
Which airline handles thunderstorms best at IAH?
Based on historical data, Delta Air Lines has the best on-time performance at IAH with a 81% on-time rate. However, all airlines are subject to the same runway and ground stop constraints during severe weather.
Do I get a refund if my IAH flight is cancelled due to thunderstorms?
Yes. Under federal law (14 CFR Part 260), you are entitled to a full cash refund if your flight is cancelled — regardless of the reason, including weather. The airline must refund to your original payment method within 7 business days for credit cards.
How long do thunderstorms delays last at IAH?
1-3 hours after cells pass. Ground stops lift quickly, but cascading delays from rerouted aircraft can persist into the evening.
Other airports affected by thunderstorms