Route reliability record
TUL→IAH
Tulsa to Houston
- Flights
- 1,123
- Period
- July 2025 to June 2026
- Distance
- 429 mi
- Carriers
- 2
This route earns a B+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.6%. When something does go wrong the average delay runs an hour and a half. That rests on 1,123 TUL to IAH flights, with a median arrival 10 minutes early.
Best time to fly TUL to IAH: a 5am–8am departure, ideally on a Thursday. Flights in that window arrived on time 95.0% of the time and Thursday flights 90.3%, against 84.5% for the route overall.
Set against the rest of the country, this route's record is 7 points better than the US average of 77.6%. That gap is worth roughly 69 fewer late arrivals for every thousand flights.
Key figures
On time
84.5%
Arrivals under 15 minutes late, of 1,113 completed flights
Avg delay
86 min
Across delayed arrivals only, not all flights
Cancelled
0.53%
National rate is 1.81%
Best carrier
SkyWest
82.6% on time across 787 flights
These figures cover 1,123 flights between July 2025 and June 2026. The median arrival is 10 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 airline is most reliable on TUL to IAH
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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlinesthin sample | 336 | 89.2% | 66 min | 0.89% | A+ |
| SkyWest Airlines | 787 | 82.6% | 91 min | 0.38% | B+ |
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 18 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–8am184 flights95.0%
- 8am–11am131 flights84.0%
- 11am–2pm297 flights90.5%
- 2pm–5pm405 flights77.1%
- 5pm–8pm106 flights79.2%
- 8pm–5am—
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 95.0% of the time, against 77.1% for the afternoon window. That is 18 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 405 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 19 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 May, when the on-time rate falls to 75.0%. February is the strongest month at 94.2%. Moving a flexible trip across that boundary buys 19 points. November was the busiest month here, with 143 flights.
Across the week, Thursday is the strongest day at 90.3% on time and Friday the weakest at 81.2%. 9 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
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 15,000 reported delay minutes.
- 35%Late-arriving aircraft
- 29%Carrier
- 27%National Airspace System
- 9%Extreme weather
35% 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 15,000 reported delay minutes here, that single category outweighs weather by 4 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 14,768 reported delay minutes.
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 95.0% on time here.
Cancellations are rare at 0.53%, below the national 1.81% 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.
Connections and stage length
What a delay here actually costs
7.1% of arrivals land an hour or more late, close to the national 8.1%. 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 an hour and a half, which a normal layover absorbs.
At 429 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 80.9% on time across 1,122 flights, 4 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 4 points of difference.
The sample behind these figures is 1,123 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
Work out the risk of missing a connection in IAH after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 94.2% on time and May 75.0%, a swing of 19 points. If the dates move at all, move them out of May before you think about anything else. 1,113 completed flights over 12 months sit behind that.
Common questions
TUL to IAH questions
How often is TUL to IAH delayed?
About one flight in six arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 15.5% of the 1,123 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.
How reliable is TUL to IAH compared with the rest of the country?
84.5% of flights arrive on time here against a national 77.6%, a difference of 7 points in its favour. That is worth a B+ on this site's grading scale.
What time of day has the fewest delays on TUL to IAH?
The 5am–8am departure window is the strongest at 95.0% on time. The 2pm–5pm window is the weakest at 77.1%, 18 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 May delays on TUL to IAH?
May is the weakest month at 75.0% on time, compared with 94.2% in February. Across the year that is 19 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
- IAH to TUL — the return legseparate record
- George Bush Intercontinental (IAH) delay statistics
- United Airlines on TUL to IAH89.2%
- SkyWest Airlines on TUL to IAH82.6%
- TUL to DFW, a related route77.8%
- ORD to IAH, a related route75.0%
- TUL to DEN, a related route79.8%
- United Airlines on-time record89.2%
- SkyWest Airlines on-time record82.6%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. TUL to IAH and IAH to TUL are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.