Flight number record

UA 1738

United Airlines · Washington to Chicago

Route: IAD → ORD
Departs: 22:30
Flights: 361
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s UA 1738, check with United Airlines.

UA 1738 lands a B, 2 points better than the national rate of 77.6%. 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 is a workable record, not a spotless one. That rests on 361 flights, with a median arrival 7 minutes early.

On time

79.4%

Arrivals under 15 minutes late, of 354 completed flights

Avg delay

80 min

Across delayed arrivals only, not all flights

Cancelled

1.66%

National rate is 1.81%

1 hour+ late

8.8%

National rate is 8.1%

These figures cover 361 flights between July 2025 and June 2026. Beyond the headline rate, 8.8% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

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 361 flights, with 22:10 (65 flights) and 22:35 (52 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 22:3074 flights20.5%
Departs 22:1065 flights18.0%
Departs 22:3552 flights14.4%

Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.

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 70.5%, and UA 1738 runs 9 points better at 79.4%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.

Against the route

UA 1738 next to IAD to ORD

Every carrier on IAD to ORD combined arrived on time 75.2% of the time across 2,054 flights, so UA 1738 is 4 points ahead of it. Across its whole network United Airlines managed 79.0%, close to this flight's figure.

UA 1738 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
UA 1738thin sample	361	79.4%	80 min	1.66%	B
All United Airlines on IAD–ORD	2,054	75.2%	73 min	0.83%	B+
All carriers on IAD–ORD	2,054	75.2%	73 min	0.83%	B+
United Airlines, whole network	821,041	79.0%	72 min	1.01%	B

Across the year

UA 1738 quarter by quarter

Quarter by quarter UA 1738 held fairly steady: 79.5% in Jul–Sep 2025, 80.0% in Oct–Dec 2025, 82.6% in Jan–Mar 2026 and 75.6% in Apr–Jun 2026. A spread of 7 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202589 flights79.5%
Oct–Dec 202591 flights80.0%
Jan–Mar 202690 flights82.6%
Apr–Jun 202691 flights75.6%

Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.

By weekday, UA 1738 did best on Sunday at 86.0% on time and worst on Wednesday at 73.1%. Each day rests on about 52 flights, so a gap of 13 points is worth noticing but could still narrow in another year.

Delay causes

Why UA 1738 runs late

One category carries most of the weight here. National Airspace System accounts for 59% of the 5,808 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.

National Airspace System
59%
Carrier
19%
Late-arriving aircraft
17%
Extreme weather
5%

59% 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 3,449 minutes out of 5,808, against a national NAS share of 21%. The split is drawn from 5,808 delay minutes reported on UA 1738.

Cancellations sit at 1.66% against a national 1.81%, which is ordinary. Diversions add another 0.28%.

Connections and routes

What a delay on this flight costs

8.8% 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.

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. 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 same number turns up on one other city pair in the data, including 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. 361 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 79.4% on time with 1.66% cancelled over 361 flights. Those are rates from the past twelve months, not a forecast for any particular day.

Where to go next

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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures