Airport month record

IAHJUN

George Bush Intercontinental in June 2026

Departures: 9,903
Month: June 2026
National, same month: 74.3%
Carriers: 10

Historical statistics for June 2026, not live status or a forecast for this year’s June. For today’s conditions at IAH, see live FAA status.

IAH in June sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 4 points worse than the national rate of 74.3%. The late ones land a little over an hour behind schedule. That rests on 9,903 flights, of which Delta Air Lines flew 714 at 75.9% on time.

Delta Air Lines is the most reliable of the five carriers covered here at 75.9% on time across 714 flights.

On time

69.9%

Arrivals under 15 minutes late, of 9,791 completed departures

Avg delay

79 min

Across delayed arrivals only, not all flights

Cancelled

0.75%

Nationally in June: 1.65%

Whole year

78.4%

IAH across all twelve months

These figures cover 9,903 departures from George Bush Intercontinental in June 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

June next to IAH's other months

Against IAH's own year, June ran 9 points worse than the twelve-month rate of 78.4%, which makes it number eleven of twelve months, best first.

IAH month by month
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	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 (this page)	9,903	69.9%	79 min	0.75%	C+

Departure window

The best time of day to leave IAH in June

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 27 points, against 9 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am1,531 flights88.0%
8am–11am1,544 flights73.4%
11am–2pm1,605 flights68.2%
2pm–5pm1,768 flights64.5%
5pm–8pm1,826 flights61.0%
8pm–5am1,629 flights66.8%

Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 61.0% on time, against 88.0% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5pm–8pm window is the busiest, with 1,826 flights scheduled in it.

Across the week, Tuesday is the strongest day at 74.0% on time and Friday the weakest at 64.1%. 10 points is a smaller lever than departure hour, but it is free.

Carrier by carrier

Which airlines ran best at IAH in June

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 75.9% of the time; Frontier Airlines manages 66.6%. Sample sizes sit next to every figure, because a two-point gap across 585 flights means less than a ten-point one.

Carriers at IAH in June 2026
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	6,152	69.9%	68 min	0.11%	C+
SkyWest Airlines	1,274	68.4%	92 min	0.71%	C+
American Airlines	756	69.6%	112 min	2.78%	C
Delta Air Lines	714	75.9%	74 min	0.70%	B+
Frontier Airlines	585	66.6%	82 min	2.74%	C
Alaska Airlinesthin sample	117	80.3%	80 min	0.00%	B+
JetBlue Airwaysthin sample	110	57.4%	100 min	0.91%	D+
PSA Airlinesthin sample	89	68.3%	233 min	7.87%	C−
Envoy Airthin sample	67	66.7%	194 min	5.97%	C−
Republic Airwaysthin sample	39	61.8%	116 min	10.26%	D−

Delta leads Frontier by 9 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Route by route

Busiest routes out of IAH in June

Routes from IAH in June 2026
Route	Flights	On time	Avg delay	Cancelled	Grade
IAH to ORD · Chicago	525	68.8%	97 min	2.10%	C
IAH to DFW · Dallas-Fort Worth	464	64.6%	122 min	3.66%	D−
IAH to DEN · Denver	431	71.7%	78 min	0.23%	C+
IAH to LAX · Los Angeles	397	79.2%	58 min	0.25%	B+
IAH to ATL · Atlanta	396	69.3%	65 min	1.77%	C
IAH to LGA · New Yorkthin sample	340	71.0%	75 min	0.88%	C+
IAH to SFO · San Franciscothin sample	300	57.2%	48 min	0.33%	D+
IAH to EWR · Newarkthin sample	300	70.0%	66 min	0.00%	C+
IAH to DCA · Washingtonthin sample	280	63.2%	111 min	2.50%	D
IAH to MIA · Miamithin sample	277	75.1%	71 min	0.72%	B+
IAH to LAS · Las Vegasthin sample	261	73.9%	75 min	1.53%	C
IAH to MCO · Orlandothin sample	257	74.2%	86 min	0.00%	C+
IAH to PHX · Phoenixthin sample	235	67.9%	101 min	0.43%	C+
IAH to SEA · Seattlethin sample	217	74.2%	68 min	0.00%	C+
IAH to MSY · New Orleansthin sample	206	68.4%	63 min	0.00%	C+
IAH to AUS · Austinthin sample	201	73.1%	65 min	0.00%	C+
IAH to CLT · Charlottethin sample	200	74.7%	89 min	1.00%	C
IAH to PHL · Philadelphiathin sample	187	65.8%	125 min	1.60%	C
IAH to BOS · Bostonthin sample	187	67.9%	67 min	0.00%	C+
IAH to IAD · Washingtonthin sample	180	72.6%	60 min	0.00%	C+
IAH to MSP · Minneapolisthin sample	177	74.4%	100 min	0.56%	C+
IAH to DTW · Detroitthin sample	173	73.8%	56 min	0.58%	C+
IAH to SAT · San Antoniothin sample	171	69.0%	70 min	0.00%	C+
IAH to SAN · San Diegothin sample	142	71.1%	64 min	0.00%	C+
IAH to SLC · Salt Lake Citythin sample	142	77.5%	81 min	0.00%	B+

Delay causes

What held IAH up in June

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 233,000 reported delay minutes.

Late-arriving aircraft
39%
Carrier
28%
National Airspace System
22%
Extreme weather
12%
Security
0%

Extreme weather accounts for 12% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the comparison with the other months below is the more useful view of the risk. The national share is 7%, so this operation carries roughly 1.7 times the usual weather exposure. The split is drawn from 233,240 reported delay minutes.

Cancellations are rare at 0.75%, below the national 1.65% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 12.6% of arrivals land a full hour or more behind schedule, against 9.7% 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 June

For a June trip through IAH: plan on this being one of the airport's harder months. The 5am–8am departures held up best at 88.0% on time, and with 12.6% of arrivals an hour or more late, a connection here deserves more slack than the same trip in January would.

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 March76.4%
IAH in April80.4%
IAH in May77.1%

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.

Key figures