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DelayAtlas

Airport month record

HOUMAY

William P. Hobby in May 2026

Departures
4,533
Month
May 2026
National, same month
78.6%
Carriers
5
C+GRADE

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

HOU in May sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 78.6%. The late ones land about 50 minutes behind schedule. That rests on 4,533 flights, with a median arrival right on schedule.

The national on-time rate over the same period is 78.6%, so hou in may runs 7 points behind the country as a whole. Across a thousand flights that is about 67 extra late arrivals.

Key figures

On time

71.9%

Arrivals under 15 minutes late, of 4,483 completed departures

Avg delay

51 min

Across delayed arrivals only, not all flights

Cancelled

0.79%

Nationally in May: 0.92%

Whole year

76.9%

HOU across all twelve months

These figures cover 4,533 departures from William P. Hobby in May 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

May next to HOU's other months

Against HOU's own year, May ran 5 points worse than the twelve-month rate of 76.9%, which makes it number nine of twelve months, best first. Either side of it, April ran 75.8% on time and June 63.6%, so a trip moved by a few weeks would have landed in a worse stretch.

HOU month by month
MonthFlightsOn timeAvg delayCancelledGrade
July 20255,09370.7%59 min0.79%C+
August 20254,64078.2%56 min0.37%B+
September 20254,45286.1%45 min0.11%A+
October 20254,88778.0%50 min0.23%B+
November 20254,55280.1%58 min2.20%B
December 20254,63482.0%49 min0.43%B+
January 20264,08188.0%44 min2.55%A
February 20263,83284.2%48 min0.68%B+
March 20264,57867.5%54 min1.42%C
April 20264,41875.8%50 min0.14%B+
May 2026 (this page)4,53371.9%51 min0.79%C+
June 20264,51463.6%56 min0.62%D+

Departure window

The best time of day to leave HOU in May

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 33 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am467 flights91.6%
  • 8am–11am1,036 flights87.5%
  • 11am–2pm662 flights76.5%
  • 2pm–5pm925 flights59.0%
  • 5pm–8pm737 flights59.0%
  • 8pm–5am706 flights62.1%

Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 59.0% on time, against 91.6% 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 8am–11am window is the busiest, with 1,036 flights scheduled in it.

Across the week, Sunday is the strongest day at 74.1% on time and Wednesday the weakest at 67.1%. 7 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week71.7Mon73.0Tue67.1Wed72.0Thu72.1Fri72.3Sat74.1Sun
Monday: 71.7 percent on time. Tuesday: 73.0 percent on time. Wednesday: 67.1 percent on time. Thursday: 72.0 percent on time. Friday: 72.1 percent on time. Saturday: 72.3 percent on time. Sunday: 74.1 percent on time

Carrier by carrier

Which airlines ran best at HOU in May

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

Carriers at HOU in May 2026
AirlineFlightsOn timeAvg delayCancelledGrade
Southwest Airlines4,24671.3%49 min0.49%C+
Delta Air Linesthin sample11882.3%52 min4.24%B−
Envoy Airthin sample8383.3%63 min6.02%B−
SkyWest Airlinesthin sample3782.4%441 min8.11%B−
PSA Airlinesthin sample3276.7%101 min6.25%B−

Route by route

Busiest routes out of HOU in May

Routes from HOU in May 2026
RouteFlightsOn timeAvg delayCancelledGrade
HOU to DAL · Dallasthin sample35079.5%63 min1.71%B
HOU to ATL · Atlantathin sample24272.5%47 min2.07%C
HOU to PHX · Phoenixthin sample19774.0%51 min0.51%C+
HOU to MSY · New Orleansthin sample19476.8%65 min0.00%B+
HOU to MCO · Orlandothin sample18376.9%52 min0.00%B+
HOU to DEN · Denverthin sample18078.1%50 min0.56%B+
HOU to LAS · Las Vegasthin sample16167.1%46 min0.00%C+
HOU to DFW · Dallas-Fort Worththin sample15281.7%161 min6.58%B−
HOU to BNA · Nashvillethin sample15271.5%42 min0.66%C+
HOU to MDW · Chicagothin sample14970.5%50 min0.00%C+
HOU to STL · St. Louisthin sample13272.1%45 min1.52%C
HOU to BWI · Baltimorethin sample12477.4%40 min0.00%B+
HOU to LGA · New Yorkthin sample11954.4%68 min1.68%F
HOU to MAF · Midlandthin sample11479.8%55 min0.00%B+
HOU to SAT · San Antoniothin sample10369.9%59 min0.00%C+
HOU to AUS · Austinthin sample10262.4%56 min0.98%D+
HOU to OKC · Oklahoma Citythin sample10166.3%43 min0.00%C+
HOU to LAX · Los Angelesthin sample9353.8%48 min0.00%F+
HOU to TPA · Tampathin sample9369.6%43 min0.00%C+
HOU to ELP · El Pasothin sample9373.1%36 min0.00%C+
HOU to MCI · Kansas Citythin sample9271.9%46 min1.09%C
HOU to HRL · Harlingenthin sample8862.5%38 min0.00%D+
HOU to CRP · Corpus Christithin sample8872.7%41 min0.00%C+
HOU to DCA · Washingtonthin sample8869.0%49 min1.14%C
HOU to SAN · San Diegothin sample8762.4%40 min1.15%D

Delay causes

What held HOU up in May

One category carries most of the weight here. Late-arriving aircraft accounts for 46% of the 63,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

  • Late-arriving aircraft
    46%
  • Carrier
    34%
  • National Airspace System
    15%
  • Extreme weather
    5%
  • Security
    0%

46% 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 63,000 reported delay minutes here, that single category outweighs weather by 10 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 63,305 reported delay minutes.

Cancellations are rare at 0.79%, below the national 0.92% 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.

6.8% of arrivals land an hour or more late, close to the national 7.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 50 minutes, which a normal layover absorbs.

What to do with this

Flying from HOU in May

For a May trip through HOU: expect 71.9% on time and 0.79% cancelled, going by May 2026. The 5am–8am window was the strongest part of the day.

Related

Where to go next

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.