Airport month record
IAHMAR
George Bush Intercontinental in March 2026
- Departures
- 10,492
- Month
- March 2026
- National, same month
- 75.7%
- Carriers
- 10
Historical statistics for March 2026, not live status or a forecast for this year’s March. For today’s conditions at IAH, see live FAA status.
IAH in March lands a B, level with the national rate of 75.7%. About one flight in four arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That is a workable record, not a spotless one. That rests on 10,492 flights, of which United Airlines flew 6,498 at 78.9% on time.
United Airlines is the most reliable of the six carriers covered here at 78.9% on time across 6,498 flights.
Key figures
On time
76.4%
Arrivals under 15 minutes late, of 10,147 completed departures
Avg delay
95 min
Across delayed arrivals only, not all flights
Cancelled
2.89%
Nationally in March: 2.90%
Whole year
78.4%
IAH across all twelve months
These figures cover 10,492 departures from George Bush Intercontinental in March 2026. On time means an arrival less than 15 minutes after the scheduled gate time, the DOT's threshold, and the national comparison uses every US departure in the same month rather than the whole year.
Against the year
March next to IAH's other months
Against IAH's own year, March ran 2 points worse than the twelve-month rate of 78.4%, which makes it number nine of twelve months, best first. Cancellations are where March stands out: 2.89% of scheduled departures were called off, 2.5 times the airport's rate across the year. Either side of it, February ran 85.6% on time and April 80.4%, so a trip moved by a few weeks would have landed in a better stretch.
| Month | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| July 2025 | 10,311 | 68.8% | 88 min | 1.74% | C |
| August 2025 | 9,889 | 74.1% | 74 min | 0.87% | C+ |
| September 2025 | 9,493 | 85.6% | 69 min | 0.20% | A+ |
| October 2025 | 10,247 | 80.7% | 65 min | 0.30% | B+ |
| November 2025 | 10,022 | 78.2% | 73 min | 1.06% | B |
| December 2025 | 9,971 | 79.4% | 71 min | 0.60% | B+ |
| January 2026 | 9,656 | 85.7% | 74 min | 3.07% | A− |
| February 2026 | 8,976 | 85.6% | 68 min | 1.06% | A |
| March 2026 (this page) | 10,492 | 76.4% | 95 min | 2.89% | B |
| April 2026 | 10,022 | 80.4% | 69 min | 0.57% | B+ |
| May 2026 | 10,105 | 77.1% | 73 min | 0.46% | B+ |
| June 2026 | 9,903 | 69.9% | 79 min | 0.75% | C+ |
Departure window
The best time of day to leave IAH in March
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 18 points, against 20 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am1,725 flights84.2%
- 8am–11am1,523 flights79.1%
- 11am–2pm1,691 flights80.3%
- 2pm–5pm1,753 flights76.4%
- 5pm–8pm1,990 flights66.2%
- 8pm–5am1,810 flights74.0%
Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 84.2% of the time, against 66.2% for the evening window. That is 18 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 1,990 flights scheduled in it.
Across the week, Tuesday is the strongest day at 81.6% on time and Sunday the weakest at 71.7%. 10 points is a smaller lever than departure hour, but it is free.
Carrier by carrier
Which airlines ran best at IAH in March
The choice of carrier is not cosmetic here. United Airlines arrives on time 78.9% of the time; Spirit Airlines manages 58.8%. Sample sizes sit next to every figure, because a two-point gap across 477 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 6,498 | 78.9% | 87 min | 1.85% | B |
| SkyWest Airlines | 1,380 | 75.1% | 122 min | 3.62% | B− |
| Delta Air Lines | 713 | 74.6% | 90 min | 5.19% | C− |
| American Airlines | 612 | 75.6% | 130 min | 3.59% | B− |
| Spirit Airlines | 477 | 58.8% | 85 min | 8.39% | D− |
| Frontier Airlines | 450 | 65.3% | 97 min | 4.67% | C− |
| Envoy Airthin sample | 156 | 80.7% | 96 min | 3.21% | B− |
| Alaska Airlinesthin sample | 91 | 71.1% | 62 min | 1.10% | C |
| Republic Airwaysthin sample | 57 | 77.4% | 115 min | 5.26% | B− |
| JetBlue Airwaysthin sample | 31 | 77.4% | 54 min | 0.00% | B+ |
Spirit Airlines cancels 8.4% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.
Route by route
Busiest routes out of IAH in March
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| IAH to ORD · Chicago | 514 | 68.1% | 103 min | 2.53% | C |
| IAH to DFW · Dallas-Fort Worth | 488 | 80.0% | 109 min | 2.87% | B |
| IAH to LAX · Los Angeles | 446 | 85.7% | 104 min | 1.12% | A |
| IAH to ATL · Atlanta | 440 | 65.9% | 68 min | 6.82% | C− |
| IAH to DEN · Denver | 406 | 82.5% | 105 min | 1.48% | B |
| IAH to MCO · Orlando | 366 | 79.0% | 82 min | 4.37% | B− |
| IAH to MIA · Miamithin sample | 341 | 68.6% | 119 min | 2.93% | C |
| IAH to LAS · Las Vegasthin sample | 323 | 84.8% | 109 min | 2.48% | B |
| IAH to EWR · Newarkthin sample | 312 | 71.4% | 68 min | 3.21% | C− |
| IAH to SFO · San Franciscothin sample | 310 | 88.5% | 128 min | 1.61% | A |
| IAH to PHX · Phoenixthin sample | 302 | 78.4% | 85 min | 1.99% | B |
| IAH to FLL · Fort Lauderdalethin sample | 293 | 65.7% | 87 min | 3.07% | C− |
| IAH to DCA · Washingtonthin sample | 289 | 73.2% | 93 min | 3.11% | C− |
| IAH to LGA · New Yorkthin sample | 272 | 54.3% | 89 min | 9.93% | F− |
| IAH to MSY · New Orleansthin sample | 256 | 85.7% | 66 min | 1.56% | A |
| IAH to AUS · Austinthin sample | 235 | 79.0% | 92 min | 2.55% | B |
| IAH to SAT · San Antoniothin sample | 234 | 82.1% | 75 min | 2.14% | B |
| IAH to CLT · Charlottethin sample | 227 | 75.6% | 81 min | 2.64% | B |
| IAH to SLC · Salt Lake Citythin sample | 211 | 81.1% | 135 min | 1.90% | B |
| IAH to DTW · Detroitthin sample | 204 | 68.8% | 86 min | 4.90% | C− |
| IAH to MSP · Minneapolisthin sample | 166 | 77.7% | 147 min | 5.42% | B− |
| IAH to SAN · San Diegothin sample | 152 | 86.7% | 116 min | 1.32% | A |
| IAH to BOS · Bostonthin sample | 148 | 76.9% | 65 min | 0.68% | B+ |
| IAH to PHL · Philadelphiathin sample | 147 | 78.5% | 84 min | 2.04% | B |
| IAH to IAD · Washingtonthin sample | 145 | 72.0% | 79 min | 1.38% | C |
Delay causes
What held IAH up in March
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 227,000 reported delay minutes.
- 36%Late-arriving aircraft
- 33%Carrier
- 23%National Airspace System
- 8%Extreme weather
- 0%Security
36% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 227,000 reported delay minutes here, that single category outweighs weather by 5 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 226,833 reported delay minutes.
Cancellations run at 2.89%, against 2.90% nationally. That is roughly one flight in 30 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.8% of arrivals land a full hour or more behind schedule, against 9.5% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
What to do with this
Flying from IAH in March
For a March trip through IAH: expect 76.4% on time and 2.89% cancelled, going by March 2026. The 5am–8am window was the strongest part of the day.
Related
Where to go next
- George Bush Intercontinental (IAH), the whole year
- IAH in July68.8%
- IAH in August74.1%
- IAH in September85.6%
- IAH in October80.7%
- IAH in November78.2%
- IAH in December79.4%
- IAH in January85.7%
- IAH in February85.6%
- IAH in April80.4%
- IAH in May77.1%
- IAH in June69.9%
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.