Carrier route record
UABOS→IAH
United Airlines · Boston to Houston
- Flights
- 1,567
- Period
- July 2025 to June 2026
- Share of route
- 77%
- Carriers
- 2
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on BOS to IAH lands a B, 6 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 1,567 flights, with a median arrival 13 minutes early.
Set against the rest of the country, United's BOS to IAH record is 6 points better than the US average of 77.6%. That gap is worth roughly 62 fewer late arrivals for every thousand flights.
Key figures
On time
83.8%
Arrivals under 15 minutes late, of 1,539 completed flights
Avg delay
71 min
Across delayed arrivals only, not all flights
Cancelled
1.47%
National rate is 1.81%
Whole route
81.8%
Every carrier on BOS to IAH, 2,027 flights
These figures cover 1,567 flights between July 2025 and June 2026. The median arrival is 13 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
United against every carrier on BOS to IAH
United flew 1,567 of the 2,027 flights on BOS to IAH, most of the route. Its 83.8% on time is 2 points better than the route as a whole, which runs 81.8%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from United at 83.8% to JetBlue at 75.1%.
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 (this page) | 1,567 | 83.8% | 71 min | 1.47% | B |
| JetBlue Airways | 460 | 75.1% | 56 min | 1.30% | B |
Flight by flight
United flight numbers on BOS to IAH
Departure window
When United runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 28 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–8am455 flights94.2%
- 8am–11am165 flights91.9%
- 11am–2pm326 flights86.9%
- 2pm–5pm368 flights76.6%
- 5pm–8pm253 flights66.7%
- 8pm–5am—
Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 94.2% of the time, against 66.7% for the evening window. That is 28 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 455 flights scheduled in it.
Across the year
United on BOS to IAH through the year
Delays peak in May, when the on-time rate falls to 72.1%. February is the strongest month at 92.1%. Moving a flexible trip across that boundary buys 20 points. July was the busiest month here, with 154 flights.
Across the week, Monday is the strongest day at 87.2% on time and Friday the weakest at 79.1%. 8 points is a smaller lever than departure hour, but it is free.
Delay causes
Why United runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 56% of the 18,000 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.
- 56%Late-arriving aircraft
- 28%National Airspace System
- 16%Carrier
- 1%Extreme weather
56% 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 18,000 reported delay minutes here, that single category outweighs weather by 56 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 17,790 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 94.2% on time here.
Cancellations sit at 1.47% against a national 1.81%, which is ordinary. Diversions add another 0.32%.
Connections and stage length
What a delay here costs
5.6% 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 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 75.9% on time across 1,565 flights, 8 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 8 points of difference.
The sample behind these figures is 1,567 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.
What to do with this
Booking United on BOS to IAH
Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 92.1% on time and May 72.1%, a swing of 20 points. If the dates move at all, move them out of May before you think about anything else. 1,539 completed flights over 12 months sit behind that.
Related
Where to go next
- BOS to IAH, every carrier
- United on IAH to BOS, the return leg
- JetBlue Airways on BOS to IAH75.1%
- United Airlines network-wide record
- Boston Logan International (BOS) delay statistics
- George Bush Intercontinental (IAH) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
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.