Route reliability record
OKC→IAH
Oklahoma City to Houston
- Flights
- 1,224
- Period
- September 2025 to August 2026
- Distance
- 395 mi
- Carriers
- 2
This route earns an A. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.3%. When something does go wrong the average delay runs a little over an hour. That rests on 1,224 OKC to IAH flights, with a median arrival 9 minutes early.
Best time to fly OKC to IAH: a 8am–11am departure, ideally on a Wednesday. Flights in that window arrived on time 90.1% of the time and Wednesday flights 92.5%, against 85.1% for the route overall.
Set against the rest of the country, this route's record is 8 points better than the US average of 77.3%. That gap is worth roughly 78 fewer late arrivals for every thousand flights.
Key figures
On time
85.1%
Arrivals under 15 minutes late, of 1,210 completed flights
Avg delay
77 min
Across delayed arrivals only, not all flights
Cancelled
1.06%
National rate is 1.89%
Best carrier
SkyWest
86.8% on time across 889 flights
These figures cover 1,224 flights between September 2025 and August 2026. The median arrival is 9 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.
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Carrier by carrier
Which airline is most reliable on OKC 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 |
|---|---|---|---|---|---|
| SkyWest Airlines | 889 | 86.8% | 82 min | 1.01% | A |
| United Airlinesthin sample | 335 | 80.7% | 68 min | 1.19% | B |
Flight by flight
Flights on OKC to IAH
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.
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Best ways to make this trip
The most reliable ways to fly Oklahoma City to Houston
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. OKC → IAHOklahoma City to Houston | SkyWest Airlines | 85.9% | 86.8% | 1.01% | 5am–8am, Wed | OO 5531 13:45 |
| 2. OKC → HOUOklahoma City to Houston | Southwest Airlines | 81.6% | 82.2% | 0.74% | 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 18 points, against half a point between the best and worst carrier.
- 5am–8am540 flights84.9%
- 8am–11am195 flights90.1%
- 11am–2pm299 flights87.9%
- 2pm–5pm74 flights82.4%
- 5pm–8pm116 flights72.4%
- 8pm–5am—
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 90.1% of the time, against 72.4% for the evening 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 5am–8am window is the busiest, with 540 flights scheduled in it.
Explore
Filter OKC to IAH by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On OKC to IAH, the best departure window is 8am–11am at 90.1% on time and the worst is 5pm–8pm at 72.4%, a wide gap of 17.7 points. All US flights leaving 8am–11am ran 83.9%.
- 5–8am84.9%
- 8–11am90.1%
- 11am–2pm87.9%
- 2–5pm82.4%
- 5–8pm72.4%
- 8pm–5am—
best all US flightsScale 60% to 95%. Cells under 30 flights show a dash.
Across the year
When delays peak on this route
This route'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.
June is the worst month at 75.6% on time, 21 points below September, the best at 96.2%. 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. March was the busiest month here, with 128 flights.
Across the week, Wednesday is the strongest day at 92.5% on time and Sunday the weakest at 79.6%, a spread of 13 points.
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 14,000 reported delay minutes.
- 35%Carrier
- 29%National Airspace System
- 27%Late-arriving aircraft
- 7%Extreme weather
- 1%Security
The largest share of delay minutes, 35%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 4,910 of the 14,000 delay minutes reported here. The split is drawn from 13,895 reported delay minutes.
Cancellations sit at 1.06% against a national 1.89%, which is ordinary. Diversions add another 0.08%.
Connections and stage length
What a delay here actually costs
5.5% 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 a little over an hour, which a normal layover absorbs.
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 80.5% on time across 1,224 flights, 5 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 5 points of difference.
The sample behind these figures is 1,224 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. September runs 96.2% on time and June 75.6%, a swing of 21 points. If the dates move at all, move them out of June before you think about anything else. 1,210 completed flights over 12 months sit behind that.
Common questions
OKC to IAH questions
How often is OKC to IAH delayed?
About one flight in seven arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 14.9% of the 1,224 flights in this analysis, against 22.7% nationally. Delayed flights are late by a little over an hour on average.
How reliable is OKC to IAH compared with the rest of the country?
85.1% of flights arrive on time here against a national 77.3%, a difference of 8 points in its favour. That is worth a A on this site's grading scale.
What time of day has the fewest delays on OKC to IAH?
The 8am–11am departure window is the strongest at 90.1% on time. The 5pm–8pm window is the weakest at 72.4%, 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 June delays on OKC to IAH?
June is the weakest month at 75.6% on time, compared with 96.2% in September. 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
- IAH to OKC — the return legseparate record
- George Bush Intercontinental (IAH) delay statistics
- SkyWest Airlines on OKC to IAH86.8%
- United Airlines on OKC to IAH80.7%
- OKC to DFW, a related route79.3%
- ORD to IAH, a related route76.0%
- OKC to DEN, a related route80.5%
- SkyWest Airlines on-time record86.8%
- United Airlines on-time record80.7%
- The best time of day to fly, according to 7.05 million flight records
- Worst months to fly in the US, ranked by the data
Direction matters. OKC to IAH and IAH to OKC 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.