Flight number record
UA 1738
United Airlines · Washington to Chicago
- Route
- IAD → ORD
- Departs
- 22:30
- Flights
- 339
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 1738, check with United Airlines.
UA 1738 lands a B, about a point better than the national rate of 77.3%. Roughly one flight in five arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That rests on 339 flights, with a median arrival 7 minutes early.
Key figures
On time
78.2%
Arrivals under 15 minutes late, of 330 completed flights
Avg delay
88 min
Across delayed arrivals only, not all flights
Cancelled
2.06%
National rate is 1.89%
1 hour+ late
9.7%
National rate is 8.3%
These figures cover 339 flights between September 2025 and August 2026. Beyond the headline rate, 9.7% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When UA 1738 flies
UA 1738 flies IAD to ORD without a single fixed slot. Its most common scheduled departure was 22:30, used on 74 of 339 flights, with 22:35 (52 flights) and 22:10 (52 flights) next.
- Departs 22:3074 flights21.8%
- Departs 22:3552 flights15.3%
- Departs 22:1052 flights15.3%
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 22:30 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.1%, and UA 1738 runs 8 points better at 78.2%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
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Against the route
UA 1738 next to IAD to ORD
Every carrier on IAD to ORD combined arrived on time 74.7% of the time across 2,106 flights, so UA 1738 is 4 points ahead of it. Across its whole network United Airlines managed 78.8%, close to this flight's figure.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1738thin sample | 339 | 78.2% | 88 min | 2.06% | B |
| All United Airlines on IAD–ORD | 2,106 | 74.7% | 79 min | 0.90% | C+ |
| All carriers on IAD–ORD | 2,106 | 74.7% | 79 min | 0.90% | C+ |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 1738 quarter by quarter
UA 1738 did not run the same all year. Its best quarter was Jan–Mar 2026 at 82.6% on time and its weakest Jul–Sep 2026 at 56.8%, a swing of 26 points on roughly 85 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 202527 flights—
- Oct–Dec 202591 flights80.0%
- Jan–Mar 202690 flights82.6%
- Apr–Jun 202691 flights75.6%
- Jul–Sep 202640 flights56.8%
Scale runs 50% to 90%. Rows with fewer than 30 flights show a dash.
By weekday, UA 1738 did best on Tuesday at 85.1% on time and worst on Saturday at 70.5%. Each day rests on about 48 flights, so a gap of 15 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late UA 1738 runs when it is late
The 72 late arrivals split 23 under half an hour, 17 between 30 and 60 minutes, and 32 an hour or more.
- 15+ min early71 flights21.5%
- Within 15 min187 flights56.7%
- 15–29 min late23 flights7.0%
- 30–59 min late17 flights5.2%
- 1–2 hours late17 flights5.2%
- 2+ hours late15 flights4.5%
Scale runs 0% to 100%.
Share of 330 completed flights by arrival against schedule.
12 of 62 late departures made up the time and arrived on time, 19% of them. In the other direction, 22 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 ORD.
The worst days
Worst days for UA 1738
The latest arrival of the period was on 3 April 2026, 11 hours 29 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 3 April 2026 | 11 hours 29 minutes | National Airspace System |
| 18 July 2026 | 9 hours 24 minutes | Extreme weather |
| 8 June 2026 | 6 hours 58 minutes | National Airspace System |
| 3 July 2026 | 4 hours 50 minutes | National Airspace System |
| 26 March 2026 | 3 hours | National Airspace System |
Delay causes
Why UA 1738 runs late
National Airspace System accounts for 53% of the 6,360 delay minutes carriers reported here, and the remaining four split what is left.
- 53%National Airspace System
- 19%Carrier
- 14%Late-arriving aircraft
- 14%Extreme weather
Extreme weather accounts for 14% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the quarterly figures above are the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.3 times the usual weather exposure. The split is drawn from 6,360 delay minutes reported on UA 1738.
Cancellations sit at 2.06% against a national 1.89%, which is ordinary. Diversions add another 0.59%.
Connections and routes
What a delay on this flight costs
9.7% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
The 588 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 two other city pairs in the data, including MCI to ORD (21) and SFO to IAD (19), but none flew often enough under UA 1738 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to IAD to ORD only.
One caution: this is a thin sample. 339 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 1738
For a booking, read UA 1738 as 78.2% on time with 2.06% cancelled over 339 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- IAD to ORD, every carrier and departure
- ORD to IAD, the return direction
- United Airlines 2497 on the same route46.5%
- United Airlines 2331 on the same route79.8%
- United Airlines 1775 on the same route84.1%
- Washington Dulles International (IAD) delay statistics
- Chicago O'Hare International (ORD) 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
- How often a connection fails at the major US hubs
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.