Flight number record
UA 1788
United Airlines · Houston to Washington
- Route
- IAH → IAD
- Departs
- 16:50
- Flights
- 262
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 1788, check with United Airlines.
UA 1788 lands a B+, 6 points better than the national rate of 77.3%. 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 rests on 262 flights, with a median arrival 4 minutes early.
Set against the rest of the country, UA 1788's record is 6 points better than the US average of 77.3%. That gap is worth roughly 55 fewer late arrivals for every thousand flights.
Key figures
On time
82.8%
Arrivals under 15 minutes late, of 261 completed flights
Avg delay
72 min
Across delayed arrivals only, not all flights
Cancelled
0.38%
National rate is 1.89%
1 hour+ late
8.0%
National rate is 8.3%
These figures cover 262 flights between September 2025 and August 2026. Beyond the headline rate, 8.0% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When UA 1788 flies
UA 1788 flies IAH to IAD without a single fixed slot. Its most common scheduled departure was 16:50, used on 74 of 262 flights, with 16:40 (44 flights) and 16:45 (42 flights) next.
- Departs 16:5074 flights28.2%
- Departs 16:4044 flights16.8%
- Departs 16:4542 flights16.0%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 16:50 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 71.9%, and UA 1788 runs 11 points better at 82.8%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
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Against the route
UA 1788 next to IAH to IAD
Every carrier on IAH to IAD combined arrived on time 82.4% of the time across 1,860 flights, so UA 1788 is about level with it. Across its whole network United Airlines managed 78.8%, which this flight beats by 4 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1788thin sample | 262 | 82.8% | 72 min | 0.38% | B+ |
| All United Airlines on IAH–IAD | 1,860 | 82.4% | 62 min | 0.43% | B+ |
| All carriers on IAH–IAD | 1,860 | 82.4% | 62 min | 0.43% | B+ |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 1788 quarter by quarter
UA 1788 did not run the same all year. Its best quarter was Jul–Sep 2025 at 90.0% on time and its weakest Jan–Mar 2026 at 78.7%, a swing of 11 points on roughly 66 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202530 flights90.0%
- Oct–Dec 202592 flights84.8%
- Jan–Mar 202690 flights78.7%
- Apr–Jun 202650 flights82.0%
Scale runs 70% to 95%.
By weekday, UA 1788 did best on Thursday at 89.2% on time and worst on Friday at 73.0%. Each day rests on about 37 flights, so a gap of 16 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late UA 1788 runs when it is late
The 45 late arrivals split 15 under half an hour, 9 between 30 and 60 minutes, and 21 an hour or more.
- 15+ min early55 flights21.1%
- Within 15 min161 flights61.7%
- 15–29 min late15 flights5.7%
- 30–59 min late9 flights3.4%
- 1–2 hours late11 flights4.2%
- 2+ hours late10 flights3.8%
Scale runs 0% to 100%.
Share of 261 completed flights by arrival against schedule.
12 of 41 late departures made up the time and arrived on time, 29% of them. In the other direction, 16 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at IAD.
The worst days
Worst days for UA 1788
The latest arrival of the period was on 16 March 2026, 6 hours 6 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 16 March 2026 | 6 hours 6 minutes | Late-arriving aircraft |
| 14 February 2026 | 2 hours 56 minutes | Late-arriving aircraft |
| 14 December 2025 | 2 hours 51 minutes | Late-arriving aircraft |
| 13 March 2026 | 2 hours 41 minutes | National Airspace System |
| 27 February 2026 | 2 hours 30 minutes | Carrier |
Delay causes
Why UA 1788 runs late
Late-arriving aircraft accounts for 44% of the 3,239 delay minutes carriers reported here, and the remaining four split what is left.
- 44%Late-arriving aircraft
- 28%Carrier
- 24%National Airspace System
- 4%Extreme weather
44% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 3,239 reported delay minutes here, that single category outweighs weather by 12 to one. The split is drawn from 3,239 delay minutes reported on UA 1788.
Cancellations are rare at 0.38%, below the national 1.89% 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 routes
What a delay on this flight costs
8.0% 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.
The 1,190 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.
The same number turns up on three other city pairs in the data, including SFO to IAH (106), GJT to DEN (102) and DEN to ATW (21), but none flew often enough under UA 1788 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to IAH to IAD only.
One caution: this is a thin sample. 262 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.
What to do with this
Booking UA 1788
For a booking, read UA 1788 as 82.8% on time with 0.38% cancelled over 262 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- IAH to IAD, every carrier and departure
- IAD to IAH, the return direction
- United Airlines 2366 on the same route82.0%
- United Airlines 1549 on the same route92.0%
- George Bush Intercontinental (IAH) delay statistics
- Washington Dulles International (IAD) delay statistics
- United Airlines on-time record
- Every United Airlines flight number with a record
- The most and least reliable flight numbers in the US
- Why the first flight of the morning is statistically safest
A flight number here means United Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
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.