Route reliability record
IAH→OKC
Houston to Oklahoma City
- Flights
- 1,399
- Period
- July 2025 to June 2026
- Distance
- 395 mi
- Carriers
- 2
This route lands a B, 2 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That is a workable record, not a spotless one. That rests on 1,399 IAH to OKC flights, with a median arrival 7 minutes early.
Best time to fly IAH to OKC: a 8am–11am departure, ideally on a Thursday. Flights in that window arrived on time 97.6% of the time and Thursday flights 84.7%, against 79.3% for the route overall.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
79.3%
Arrivals under 15 minutes late, of 1,380 completed flights
Avg delay
83 min
Across delayed arrivals only, not all flights
Cancelled
1.14%
National rate is 1.81%
Best carrier
SkyWest
78.6% on time across 1,092 flights
These figures cover 1,399 flights between July 2025 and June 2026. Beyond the headline rate, 9.1% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Which airline is most reliable on IAH to OKC
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 | 307 | 82.2% | 67 min | 1.30% | B |
| SkyWest Airlines | 1,092 | 78.6% | 87 min | 1.10% | B |
Flight by flight
Flights on IAH to OKC
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
Best ways to make this trip
The most reliable ways to fly Houston to Oklahoma City
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 1 of the top 2 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. IAH → OKCHouston to Oklahoma City | SkyWest Airlines | 77.7% | 78.6% | 1.10% | 8am–11am, Thu | OO 5278 18:05 |
| 2. HOU → OKCHouston to Oklahoma City | Southwest Airlines | 76.2% | 76.8% | 0.80% | 5am–8am, Tue | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
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 25 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–8am236 flights86.8%
- 8am–11am42 flights97.6%
- 11am–2pm36 flights72.2%
- 2pm–5pm274 flights84.1%
- 5pm–8pm330 flights72.8%
- 8pm–5am481 flights76.3%
Scale runs 65% to 100%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 72.2% on time against 97.6% for 8am–11am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 8pm–5am window is the busiest, with 481 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 18 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.
June is the worst month at 70.0% on time, 18 points below October, the best at 87.6%. 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. July was the busiest month here, with 206 flights.
Across the week, Thursday is the strongest day at 84.7% on time and Saturday the weakest at 74.0%. 11 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 48% of the 24,000 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.
- 48%Late-arriving aircraft
- 32%Carrier
- 11%Extreme weather
- 9%National Airspace System
Extreme weather accounts for 11% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 1.8 times the usual weather exposure. The split is drawn from 23,773 reported delay minutes.
48% 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 24,000 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.
Cancellations sit at 1.14% against a national 1.81%, which is ordinary. Diversions add another 0.21%.
Connections and stage length
What a delay here actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.1% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
At 395 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 8am–11am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 84.3% on time across 1,399 flights, 5 points above 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 5 points of difference.
The sample behind these figures is 1,399 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 OKC 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. October runs 87.6% on time and June 70.0%, a swing of 18 points. If the dates move at all, move them out of June before you think about anything else. 1,380 completed flights over 12 months sit behind that.
Common questions
IAH to OKC questions
How often is IAH to OKC delayed?
About one flight in five arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 20.7% of the 1,399 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.
How reliable is IAH to OKC compared with the rest of the country?
79.3% of flights arrive on time here against a national 77.6%, a difference of 2 points in its favour. That is worth a B on this site's grading scale.
What time of day has the fewest delays on IAH to OKC?
The 8am–11am departure window is the strongest at 97.6% on time. The 11am–2pm window is the weakest at 72.2%, 25 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 IAH to OKC?
June is the weakest month at 70.0% on time, compared with 87.6% in October. Across the year that is 18 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
- OKC to IAH — the return legseparate record
- George Bush Intercontinental (IAH) delay statistics
- United Airlines on IAH to OKC82.2%
- SkyWest Airlines on IAH to OKC78.6%
- IAH to ORD, a related route74.8%
- DFW to OKC, a related route72.4%
- IAH to DFW, a related route75.0%
- United Airlines on-time record82.2%
- SkyWest Airlines on-time record78.6%
- 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. IAH to OKC and OKC to IAH 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.