Carrier performance at one airport
WN→HOU
Southwest Airlines at William P. Hobby
- Departures
- 50,878
- Period
- June 2025 to May 2026
- Routes
- 25
- Rank here
- #4 of 4
Southwest Airlines at Houston 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 50 minutes on average. That is a workable record, not a spotless one. That rests on 50,878 flights, of which Delta Air Lines flew 1,437 at 83.8% on time.
Measured against the airport rather than the country, Southwest Airlines runs half a point behind the 77.3% 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
77.0%
50,385 completed departures
Avg delay
51 min
Across delayed flights only
Cancelled
0.75%
At HOU, this carrier only
Rank here
#4
Of 4 carriers clearing the floor at HOU
These figures cover 51,000 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.
Against the competition
Every carrier at HOU, ranked
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 |
|---|---|---|---|---|---|
| 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− |
| Southwest Airlines (this page) | 50,878 | 77.0% | 51 min | 0.75% | 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
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 | 4,075 | 81.3% | 57 min | 2.23% | 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 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 ATL · Atlanta | 1,517 | 75.4% | 51 min | 0.79% | 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+ |
| HOU to SAN · San Diego | 958 | 76.6% | 46 min | 0.73% | B+ |
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 7 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am5,602 flights93.4%
- 8am–11am11,138 flights89.2%
- 11am–2pm8,215 flights79.2%
- 2pm–5pm8,640 flights69.2%
- 5pm–8pm8,030 flights67.8%
- 8pm–5am9,253 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 93.4% of the time, against 65.9% 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.
Across the year
Seasonal pattern
Delays peak in March, when the on-time rate falls to 66.7%. January is the strongest month at 88.3%. Moving a flexible trip across that boundary buys 22 points.
Delay causes
What holds this operation up
- 47%Late-arriving aircraft
- 31%Carrier
- 18%National Airspace System
- 4%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 591,000 reported delay minutes here, that single category outweighs weather by 12 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.
Cancellations are rare at 0.75%, below the national 1.80% 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.
6.1% 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 50 minutes kind, which a normal layover absorbs.
50,878 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 March 66.7%, a swing of 22 points. If the dates move at all, move them out of March before you think about anything else.
Common questions
Southwest Airlines at HOU
How often is Southwest Airlines at 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 23.0% of the 50,878 flights in this analysis, against 22.6% nationally. Delayed flights are late by roughly 50 minutes on average.
Which airline is most reliable on Southwest Airlines at 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 Southwest Airlines at HOU?
The 5am–8am departure window is the strongest at 93.4% on time. The 8pm–5am window is the weakest at 65.9%, 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 March delays on Southwest Airlines at HOU?
March is the weakest month at 66.7% on time, compared with 88.3% in January. Across the year that is 22 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.