Flight number record

UA 1938

United Airlines · Washington to Phoenix

Route: IAD → PHX
Departs: 17:26
Flights: 360
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s UA 1938, check with United Airlines.

UA 1938 lands a B+, level with the national rate of 77.6%. Roughly one flight in four 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 360 flights, with a median arrival 5 minutes early.

On time

77.4%

Arrivals under 15 minutes late, of 358 completed flights

Avg delay

81 min

Across delayed arrivals only, not all flights

Cancelled

0.56%

National rate is 1.81%

1 hour+ late

8.1%

National rate is 8.1%

These figures cover 360 flights between July 2025 and June 2026. Beyond the headline rate, 8.1% 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 1938 flies

UA 1938 flies IAD to PHX without a single fixed slot. Its most common scheduled departure was 17:26, used on 85 of 360 flights, with 17:50 (41 flights) and 17:24 (37 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 17:2685 flights23.6%
Departs 17:5041 flights11.4%
Departs 17:2437 flights10.3%

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 17:26 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and UA 1938 runs 9 points better at 77.4%. 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 1938 next to IAD to PHX

Every carrier on IAD to PHX combined arrived on time 79.9% of the time across 1,097 flights, so UA 1938 is 3 points behind it. United flew 760 flights on the same city pair under all its flight numbers, including this one, and those ran 84.9% on time. Across its whole network United Airlines managed 79.0%, which this flight trails by 2 points.

UA 1938 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
UA 1938thin sample	360	77.4%	81 min	0.56%	B+
All United Airlines on IAD–PHX	760	84.9%	77 min	0.79%	B+
All carriers on IAD–PHX	1,097	79.9%	63 min	0.82%	B+
United Airlines, whole network	821,041	79.0%	72 min	1.01%	B

Across the year

UA 1938 quarter by quarter

UA 1938 did not run the same all year. Its best quarter was Apr–Jun 2026 at 84.6% on time and its weakest Jul–Sep 2025 at 68.1%, a swing of 17 points on roughly 90 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 202591 flights68.1%
Oct–Dec 202588 flights77.3%
Jan–Mar 202690 flights79.5%
Apr–Jun 202691 flights84.6%

Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.

By weekday, UA 1938 did best on Tuesday at 84.9% on time and worst on Saturday at 69.4%. Each day rests on about 51 flights, so a gap of 16 points is worth noticing but could still narrow in another year.

Delay causes

Why UA 1938 runs late

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 6,555 reported delay minutes.

National Airspace System
35%
Late-arriving aircraft
34%
Carrier
21%
Extreme weather
9%

34% 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 6,555 reported delay minutes here, that single category outweighs weather by 4 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 6,555 delay minutes reported on UA 1938.

Cancellations are rare at 0.56%, below the national 1.81% 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

8.1% 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 1,956 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.

UA 1938 is not only a IAD to PHX flight. It also flew JAX to IAD (280 flights, 90.3% on time) often enough to be scored on its own. Airlines attach one number to several legs of an aircraft's day, and each leg keeps its own record here, so check which city pair is on your booking before reading a rate.

One caution: this is a thin sample. 360 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.

Other routes flown as UA 1938
Also flown as	Flights	On time	Avg delay	Cancelled	Grade
JAX to IADthin sample	280	90.3%	106 min	0.71%	A+

What to do with this

Booking UA 1938

For a booking, read UA 1938 as 77.4% on time with 0.56% cancelled over 360 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