Flight number record

UA 2311

United Airlines · Houston to Washington

Route: IAH → DCA
Departs: 09:45
Flights: 302
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s UA 2311, check with United Airlines.

UA 2311 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 roughly 50 minutes on average. That is a workable record, not a spotless one. That rests on 302 flights, with a median arrival 7 minutes early.

Set against the rest of the country, UA 2311's record is 6 points better than the US average of 77.6%. That gap is worth roughly 60 fewer late arrivals for every thousand flights.

On time

83.6%

Arrivals under 15 minutes late, of 299 completed flights

Avg delay

52 min

Across delayed arrivals only, not all flights

Cancelled

0.33%

National rate is 1.81%

1 hour+ late

4.0%

National rate is 8.1%

These figures cover 302 flights between July 2025 and June 2026. The median arrival is 7 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.

Schedule

When UA 2311 flies

UA 2311 flies IAH to DCA without a single fixed slot. Its most common scheduled departure was 09:45, used on 85 of 302 flights, with 09:50 (47 flights) and 09:30 (46 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 09:4585 flights28.1%
Departs 09:5047 flights15.6%
Departs 09:3046 flights15.2%

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 09:45 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and UA 2311 runs level with that at 83.6%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

Against the route

UA 2311 next to IAH to DCA

Every carrier on IAH to DCA combined arrived on time 74.8% of the time across 3,202 flights, so UA 2311 is 9 points ahead of it. United flew 2,413 flights on the same city pair under all its flight numbers, including this one, and those ran 75.2% on time. Across its whole network United Airlines managed 79.0%, which this flight beats by 5 points.

UA 2311 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
UA 2311thin sample	302	83.6%	52 min	0.33%	B+
All United Airlines on IAH–DCA	2,413	75.2%	70 min	0.79%	B+
All carriers on IAH–DCA	3,202	74.8%	73 min	1.81%	C
United Airlines, whole network	821,041	79.0%	72 min	1.01%	B

Across the year

UA 2311 quarter by quarter

UA 2311 did not run the same all year. Its best quarter was Oct–Dec 2025 at 87.7% on time and its weakest Apr–Jun 2026 at 76.3%, a swing of 11 points on roughly 76 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 202579 flights85.9%
Oct–Dec 202573 flights87.7%
Jan–Mar 202674 flights84.7%
Apr–Jun 202676 flights76.3%

Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.

By weekday, UA 2311 ranged from 77.6% on Monday to 88.2% on Tuesday. With about 43 flights behind each day, a spread of 11 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why UA 2311 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 2,567 reported delay minutes.

Carrier
30%
National Airspace System
27%
Late-arriving aircraft
24%
Extreme weather
19%

Extreme weather accounts for 19% 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 3.1 times the usual weather exposure. The split is drawn from 2,567 delay minutes reported on UA 2311.

Cancellations are rare at 0.33%, 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

Badly late arrivals are rare here: only 4.0% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

The 1,208 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 five other city pairs in the data, including LAX to IAH (36), ORD to RSW (9) and MIA to ORD (6), but none flew often enough under UA 2311 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to IAH to DCA only.

One caution: this is a thin sample. 302 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 2311

For a booking, read UA 2311 as 83.6% on time with 0.33% cancelled over 302 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