Route reliability record
RSW→IAH
Fort Myers to Houston
- Flights
- 878
- Period
- July 2025 to June 2026
- Distance
- 861 mi
- Carriers
- 1
This route earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 10 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 878 RSW to IAH flights, with a median arrival 18 minutes early.
Best time to fly RSW to IAH: a 11am–2pm departure, ideally on a Thursday. Flights in that window arrived on time 97.5% of the time and Thursday flights 91.4%, against 87.8% for the route overall.
Set against the rest of the country, this route's record is 10 points better than the US average of 77.6%. That gap is worth roughly 102 fewer late arrivals for every thousand flights.
Key figures
On time
87.8%
Arrivals under 15 minutes late, of 874 completed flights
Avg delay
91 min
Across delayed arrivals only, not all flights
Cancelled
0.34%
National rate is 1.81%
Best carrier
United
87.8% on time across 878 flights
These figures cover 878 flights between July 2025 and June 2026. The median arrival is 18 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 RSW 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 Airlines | 878 | 87.8% | 91 min | 0.34% | A+ |
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 22 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–8am277 flights94.2%
- 8am–11am50 flights94.0%
- 11am–2pm199 flights97.5%
- 2pm–5pm18 flights—
- 5pm–8pm334 flights75.9%
- 8pm–5am—
Scale runs 65% to 100%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 11am–2pm slot at 97.5% on time, ahead of 5pm–8pm at 75.9%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 5pm–8pm window is the busiest, with 334 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 23 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.
August is the worst month at 74.0% on time, 23 points below January, the best at 96.7%. 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. January was the busiest month here, with 93 flights.
Across the week, Thursday is the strongest day at 91.4% on time and Sunday the weakest at 84.4%. 7 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 9,747 reported delay minutes.
- 41%Late-arriving aircraft
- 35%National Airspace System
- 16%Carrier
- 8%Extreme weather
41% 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 9,747 reported delay minutes here, that single category outweighs weather by 5 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 9,747 reported delay minutes.
35% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 3,437 minutes out of 9,747, against a national NAS share of 21%.
Cancellations are rare at 0.34%, 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
6.1% 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.
The 861 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 84.3% on time across 877 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.
One caution: this is a thin sample. 878 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
Work out the risk of missing a connection in IAH after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 878 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 87.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 874 completed flights over 12 months sit behind that.
Common questions
RSW to IAH questions
How often is RSW to IAH delayed?
About one flight in eight arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 12.2% of the 878 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.
How reliable is RSW to IAH compared with the rest of the country?
87.8% of flights arrive on time here against a national 77.6%, a difference of 10 points in its favour. That is worth a A+ on this site's grading scale.
What time of day has the fewest delays on RSW to IAH?
The 11am–2pm departure window is the strongest at 97.5% on time. The 5pm–8pm window is the weakest at 75.9%, 22 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 August delays on RSW to IAH?
August is the weakest month at 74.0% on time, compared with 96.7% in January. Across the year that is 23 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 RSW — the return legseparate record
- Southwest Florida International (RSW) delay statistics
- George Bush Intercontinental (IAH) delay statistics
- RSW to ORD, a related route76.5%
- ORD to IAH, a related route75.0%
- RSW to ATL, a related route85.7%
- United Airlines on-time record87.8%
- 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. RSW to IAH and IAH to RSW 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.