Route reliability record
BOS→IAH
Boston to Houston
- Flights
- 2,018
- Period
- September 2025 to August 2026
- Distance
- 1,597 mi
- Carriers
- 2
This route lands a B, 3 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That rests on 2,018 BOS to IAH flights, of which United Airlines flew 1,550 at 82.3% on time.
Best time to fly BOS to IAH: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 92.7% of the time and Wednesday flights 85.5%, against 80.1% for the route overall.
The US average over the same twelve months is 77.3%, 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
80.1%
Arrivals under 15 minutes late, of 1,982 completed flights
Avg delay
69 min
Across delayed arrivals only, not all flights
Cancelled
1.68%
National rate is 1.89%
Best carrier
United
82.3% on time across 1,550 flights
These figures cover 2,018 flights between September 2025 and August 2026. The median arrival is 11 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 BOS to IAH
The choice of carrier is not cosmetic here. United Airlines arrives on time 82.3% of the time; JetBlue Airways manages 72.7%. Sample sizes sit next to every figure, because a two-point gap across 468 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 1,550 | 82.3% | 75 min | 1.29% | B |
| JetBlue Airways | 468 | 72.7% | 58 min | 2.99% | C |
United leads JetBlue by 10 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Flight by flight
Flights on BOS 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 Boston to Houston
Every airline on this route, ranked by how often a scheduled flight actually operated and arrived on time, with its best departure time and most punctual flight number. No nearby airport pair beat these.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. BOS → IAHBoston to Houston | United Airlines | 81.2% | 82.3% | 1.29% | 5am–8am, Wed | UA 226 07:25 |
| 2. BOS → IAHBoston to Houston | JetBlue Airways | 70.5% | 72.7% | 2.99% | 5am–8am, Tue | B6 2033 09:15 |
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 29 points, against 10 points between the best and worst carrier.
- 5am–8am471 flights92.7%
- 8am–11am464 flights82.5%
- 11am–2pm389 flights84.3%
- 2pm–5pm442 flights69.9%
- 5pm–8pm252 flights63.6%
- 8pm–5am—
Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 63.6% on time, against 92.7% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5am–8am window is the busiest, with 471 flights scheduled in it.
Explore
Filter BOS 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 BOS to IAH, the best departure window is 5am–8am at 92.7% on time and the worst is 5pm–8pm at 63.6%, a wide gap of 29.1 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am92.7%
- 8–11am82.5%
- 11am–2pm84.3%
- 2–5pm69.9%
- 5–8pm63.6%
- 8pm–5am—
best all US flightsScale 55% 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.
July is the worst month at 70.5% on time, 21 points below April, the best at 91.4%. 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 210 flights.
Across the week, Wednesday is the strongest day at 85.5% on time and Thursday the weakest at 76.9%, a spread of 9 points.
Delay causes
Why this route gets delayed
Late-arriving aircraft accounts for 44% of the 27,000 delay minutes carriers reported here, and the remaining four split what is left.
- 44%Late-arriving aircraft
- 29%National Airspace System
- 24%Carrier
- 2%Extreme weather
- 0%Security
44% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 27,000 reported delay minutes here, that single category outweighs weather by 18 to one. The split is drawn from 27,309 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 92.7% on time here.
Cancellations sit at 1.68% against a national 1.89%, which is ordinary. Diversions add another 0.10%.
Connections and stage length
What a delay here actually costs
7.2% 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 1,597 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 71.5% on time across 2,017 flights, 9 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 9 points of difference.
The sample behind these figures is 2,018 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. April runs 91.4% on time and July 70.5%, a swing of 21 points. If the dates move at all, move them out of July before you think about anything else. 1,982 completed flights over 12 months sit behind that.
Common questions
BOS to IAH questions
How often is BOS to IAH 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 19.9% of the 2,018 flights in this analysis, against 22.7% nationally. Delayed flights are late by a little over an hour on average.
Which airline is most reliable on BOS to IAH?
United Airlines leads at 82.3% on time across 1,550 flights. JetBlue Airways is at the other end on 72.7%, a gap of 10 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 BOS to IAH?
The 5am–8am departure window is the strongest at 92.7% on time. The 5pm–8pm window is the weakest at 63.6%, 29 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 July delays on BOS to IAH?
July is the weakest month at 70.5% on time, compared with 91.4% in April. 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 BOS — the return legseparate record
- Boston Logan International (BOS) delay statistics
- George Bush Intercontinental (IAH) delay statistics
- United Airlines on BOS to IAH82.3%
- JetBlue Airways on BOS to IAH72.7%
- BOS to DCA, a related route72.6%
- ORD to IAH, a related route76.0%
- BOS to ORD, a related route71.9%
- United Airlines on-time record82.3%
- JetBlue Airways on-time record72.7%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Direction matters. BOS to IAH and IAH to BOS 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.