Carrier performance at one airport
WN→HOU
Southwest Airlines at William P. Hobby
- Departures
- 49,994
- Period
- September 2025 to August 2026
- Routes
- 25
- Rank here
- #4 of 5
Southwest Airlines at Houston lands a B+, about a point worse than the national rate of 77.3%. About one flight in four arrives 15 minutes late or worse, and those flights are late by about 50 minutes on average. That rests on 49,994 flights, of which Delta Air Lines flew 1,387 at 84.6% on time.
Measured against the airport rather than the country, Southwest Airlines runs half a point behind the 76.5% weighted average across all carriers at HOU. That is the comparison worth making: every operator here works the same runways, the same airspace and the same weather.
Key figures
On time
76.2%
49,513 completed departures
Avg delay
50 min
Across delayed flights only
Cancelled
0.71%
At HOU, this carrier only
Rank here
#4
Of 5 carriers clearing the floor at HOU
These figures cover 50,000 flights between September 2025 and August 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.
Against the competition
Every carrier at HOU, ranked
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 84.6% of the time; SkyWest Airlines manages 73.2%. Sample sizes sit next to every figure, because a two-point gap across 449 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 1,387 | 84.6% | 96 min | 2.09% | B |
| Envoy Air | 804 | 83.4% | 68 min | 2.74% | B |
| PSA Airlines | 719 | 77.9% | 106 min | 5.01% | B− |
| Southwest Airlines (this page) | 49,994 | 76.2% | 50 min | 0.71% | B+ |
| SkyWest Airlines | 449 | 73.2% | 135 min | 4.45% | C− |
PSA Airlines cancels 5.0% 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
Where Southwest Airlines flies from HOU
Southwest Airlines operates 25 routes out of HOU with enough volume to report. Route records inside one carrier at one airport still spread widely, because a short shuttle and a transcontinental have very different exposure to a late inbound.
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| HOU to DAL · Dallas | 4,039 | 81.6% | 56 min | 2.10% | B |
| HOU to DEN · Denver | 2,369 | 77.4% | 53 min | 0.34% | B+ |
| HOU to MSY · New Orleans | 2,289 | 82.6% | 51 min | 0.22% | B+ |
| HOU to PHX · Phoenix | 2,081 | 76.8% | 50 min | 0.53% | B+ |
| HOU to MCO · Orlando | 2,057 | 77.0% | 51 min | 0.78% | B+ |
| HOU to LAS · Las Vegas | 2,018 | 79.8% | 51 min | 0.35% | B+ |
| HOU to MDW · Chicago | 1,843 | 70.6% | 49 min | 0.98% | C+ |
| HOU to BNA · Nashville | 1,835 | 77.2% | 49 min | 0.65% | B+ |
| HOU to STL · St. Louis | 1,567 | 79.8% | 50 min | 0.45% | B+ |
| HOU to BWI · Baltimore | 1,482 | 74.9% | 47 min | 1.35% | C |
| HOU to ATL · Atlanta | 1,464 | 74.2% | 50 min | 0.61% | C+ |
| HOU to MAF · Midland | 1,363 | 82.3% | 53 min | 0.44% | B+ |
| HOU to LGA · New York | 1,358 | 62.5% | 64 min | 2.65% | D |
| HOU to AUS · Austin | 1,315 | 74.4% | 49 min | 0.38% | C+ |
| HOU to SAT · San Antonio | 1,282 | 77.1% | 51 min | 0.08% | B+ |
| HOU to OKC · Oklahoma City | 1,216 | 75.7% | 48 min | 0.90% | B+ |
| HOU to LAX · Los Angeles | 1,188 | 73.6% | 45 min | 0.17% | C+ |
| HOU to HRL · Harlingen | 1,165 | 75.9% | 44 min | 0.17% | B+ |
| HOU to DCA · Washington | 1,052 | 68.3% | 54 min | 1.81% | C |
| HOU to ELP · El Paso | 1,041 | 77.0% | 45 min | 0.29% | B+ |
| HOU to TPA · Tampa | 1,010 | 73.4% | 51 min | 0.40% | C+ |
| HOU to MCI · Kansas City | 1,003 | 76.9% | 50 min | 0.40% | B+ |
| HOU to CRP · Corpus Christi | 985 | 77.5% | 50 min | 0.10% | B+ |
| HOU to SAN · San Diego | 985 | 73.9% | 45 min | 0.71% | C+ |
| HOU to ABQ · Albuquerque | 979 | 79.8% | 47 min | 0.51% | B+ |
Flight by flight
Southwest Airlines flight numbers from HOU
2 Southwest Airlines flight numbers leaving HOU flew their main route often enough to have a record of their own. Grouped by destination.
Departure window
Best time of day for this operation
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 28 points, against 11 points between the best and worst carrier.
- 5am–8am5,603 flights93.1%
- 8am–11am10,744 flights89.0%
- 11am–2pm7,948 flights79.6%
- 2pm–5pm9,064 flights67.2%
- 5pm–8pm7,943 flights65.6%
- 8pm–5am8,692 flights65.6%
Scale runs 55% to 100%.
Book the early departure. Flights leaving between 5am–8am arrive on time 93.1% of the time, against 65.6% for the overnight window. That is 28 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 10,744 flights scheduled in it.
Across the year
Seasonal pattern
June is the worst month at 62.9% on time, 25 points below January, the best at 88.3%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. October was the busiest month here, with 4,550 flights.
Delay causes
What holds this operation up
- 46%Late-arriving aircraft
- 33%Carrier
- 18%National Airspace System
- 3%Extreme weather
- 1%Security
46% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 586,000 reported delay minutes here, that single category outweighs weather by 16 to one. The split is drawn from 585,784 reported delay minutes.
Cancellations are rare at 0.71%, below the national 1.89% 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.
6.2% of arrivals land an hour or more late, close to the national 8.3%, so 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.
49,994 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.
Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 88.3% on time and June 62.9%, a swing of 25 points. If the dates move at all, move them out of June before you think about anything else. 49,513 completed flights over 12 months sit behind that.
Common questions
Southwest Airlines at HOU
How often is Southwest Airlines at HOU delayed?
About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 23.8% of the 49,994 flights in this analysis, against 22.7% nationally. Delayed flights are late by about 50 minutes on average.
Which airline is most reliable on Southwest Airlines at HOU?
Delta Air Lines leads at 84.6% on time across 1,387 flights. SkyWest Airlines is at the other end on 73.2%, a gap of 11 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 Southwest Airlines at HOU?
The 5am–8am departure window is the strongest at 93.1% on time. The 8pm–5am window is the weakest at 65.6%, 28 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 June delays on Southwest Airlines at HOU?
June is the weakest month at 62.9% on time, compared with 88.3% in January. Across the year that is 25 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.