Houston, TX · departure reliability
HOU
William P. Hobby
- Departures
- 54,632
- Period
- June 2025 to May 2026
- Carriers
- 4
- US rank
- #37 by volume
Houston
William P. Hobby lands a B+, level with the national rate of 77.4%. Roughly one flight in four arrive 15 minutes late or worse, and those flights are late by roughly 55 minutes on average. That is a workable record, not a spotless one. That rests on 54,632 flights, of which Delta Air Lines flew 1,437 at 83.8% on time.
Delta Air Lines is the most reliable of the four carriers covered here at 83.8% on time across 1,437 flights.
Key figures
On time
77.2%
Departures arriving under 15 minutes late at their destination
Avg delay
53 min
Across delayed flights only
Cancelled
0.92%
National rate is 1.80%
Best carrier
Delta
83.8% on time here
These figures cover 55,000 flights between June 2025 and May 2026. The median arrival is 3 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Carrier by carrier
Which airlines run best out of HOU
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 83.8% of the time; Southwest Airlines manages 77.0%. Sample sizes sit next to every figure, because a two-point gap across 50,878 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Southwest Airlines | 50,878 | 77.0% | 51 min | 0.75% | B+ |
| Delta Air Lines | 1,437 | 83.8% | 95 min | 2.02% | B |
| Envoy Air | 1,103 | 80.4% | 72 min | 2.81% | B |
| PSA Airlines | 616 | 77.2% | 104 min | 5.68% | B− |
PSA Airlines cancels 5.7% 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 HOU
Route-level records vary far more than the airport average. These are the 25 busiest departures from HOU, each with its own on-time rate against the airport-wide 77.2%.
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| HOU to DAL · Dallas | 4,075 | 81.3% | 57 min | 2.23% | B |
| HOU to ATL · Atlanta | 2,953 | 79.4% | 68 min | 1.39% | B |
| HOU to DEN · Denver | 2,349 | 77.4% | 54 min | 0.51% | B+ |
| HOU to MSY · New Orleans | 2,265 | 83.1% | 51 min | 0.26% | B+ |
| HOU to PHX · Phoenix | 2,154 | 78.5% | 52 min | 0.60% | B+ |
| HOU to LAS · Las Vegas | 2,074 | 80.5% | 48 min | 0.43% | B+ |
| HOU to DFW · Dallas-Fort Worth | 2,074 | 77.7% | 88 min | 4.29% | B− |
| HOU to MCO · Orlando | 2,028 | 77.1% | 53 min | 0.84% | B+ |
| HOU to MDW · Chicago | 1,844 | 74.3% | 49 min | 1.19% | C |
| HOU to BNA · Nashville | 1,804 | 78.2% | 47 min | 0.67% | B+ |
| HOU to STL · St. Louis | 1,550 | 80.4% | 52 min | 0.32% | B+ |
| HOU to BWI · Baltimore | 1,462 | 75.2% | 50 min | 1.78% | B |
| HOU to AUS · Austin | 1,446 | 74.3% | 50 min | 0.35% | C+ |
| HOU to SAT · San Antonio | 1,408 | 79.1% | 50 min | 0.00% | B+ |
| HOU to LGA · New York | 1,359 | 66.4% | 64 min | 2.65% | C |
| HOU to MAF · Midland | 1,357 | 82.8% | 49 min | 0.44% | B+ |
| HOU to OKC · Oklahoma City | 1,269 | 76.9% | 51 min | 0.87% | B+ |
| HOU to HRL · Harlingen | 1,224 | 76.1% | 49 min | 0.16% | B+ |
| HOU to LAX · Los Angeles | 1,194 | 76.6% | 47 min | 0.17% | B+ |
| HOU to DCA · Washington | 1,056 | 70.4% | 57 min | 1.33% | C |
| HOU to ELP · El Paso | 1,052 | 79.3% | 48 min | 0.38% | B+ |
| HOU to TPA · Tampa | 1,026 | 76.6% | 50 min | 0.39% | B+ |
| HOU to MCI · Kansas City | 1,003 | 75.9% | 49 min | 0.60% | B+ |
| HOU to ABQ · Albuquerque | 980 | 79.7% | 53 min | 0.51% | B+ |
| HOU to CRP · Corpus Christi | 974 | 78.2% | 57 min | 0.31% | B+ |
Departure window
The best time of day to leave HOU
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 27 points, against 7 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am6,321 flights93.0%
- 8am–11am12,062 flights89.0%
- 11am–2pm8,744 flights79.3%
- 2pm–5pm9,261 flights69.4%
- 5pm–8pm8,738 flights68.2%
- 8pm–5am9,506 flights65.9%
Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 93.0% of the time, against 65.9% for the overnight window. That is 27 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on.
Across the year
When HOU runs late
HOU's year swings by 21 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
Delays peak in March, when the on-time rate falls to 67.5%. January is the strongest month at 88.0%. Moving a flexible trip across that boundary buys 21 points.
Across the week, Tuesday is the strongest day at 82.0% on time and Sunday the weakest at 72.9%. 9 points is a smaller lever than departure hour, but it is free.
Delay causes
Why HOU gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 47% of the 655,000 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.
- 47%Late-arriving aircraft
- 31%Carrier
- 17%National Airspace System
- 5%Extreme weather
- 0%Security
47% 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 655,000 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 practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 93.0% on time here.
Cancellations sit at 0.92% against a national 1.80%, which is ordinary. Diversions add another 0.22%.
6.2% of arrivals land an hour or more late, close to the national 8.2%. 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 are the roughly 55 minutes kind, which a normal layover absorbs.
54,632 flights sit behind these numbers, which is a large enough sample that the headline rate is not moving on noise. Where a sub-group falls below 30 flights the site shows a dash instead of a percentage.
What to do with this
Flying out of HOU
Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 88.0% on time and March 67.5%, a swing of 21 points. If the dates move at all, move them out of March before you think about anything else.
Common questions
HOU delay questions
How often is Houston (HOU) delayed?
Roughly one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 22.8% of the 54,632 flights in this analysis, against 22.6% nationally. Delayed flights are late by roughly 55 minutes on average.
Which airline is most reliable on Houston (HOU)?
Delta Air Lines leads at 83.8% on time across 1,437 flights. Southwest Airlines is at the other end on 77.0%, a gap of 7 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on Houston (HOU)?
The 5am–8am departure window is the strongest at 93.0% on time. The 8pm–5am window is the weakest at 65.9%, 27 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are March delays on Houston (HOU)?
March is the weakest month at 67.5% on time, compared with 88.0% in January. Across the year that is 21 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
Source: US DOT Bureau of Transportation Statistics, on-time performance data, June 2025 to May 2026. Updated monthly. How this data is collected.