Flight number record

UA 1524

United Airlines · Washington to Houston

Route: IAD → IAH
Departs: 08:30
Flights: 334
Period: September 2025 to August 2026

Historical statistics for September 2025 to August 2026, not live status. For today’s UA 1524, check with United Airlines.

UA 1524 earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 13 points better than the national rate of 77.3%. When something does go wrong the average delay runs a little over an hour. That rests on 334 flights, with a median arrival 15 minutes early.

Set against the rest of the country, UA 1524's record is 13 points better than the US average of 77.3%. That gap is worth roughly 125 fewer late arrivals for every thousand flights.

On time

89.8%

Arrivals under 15 minutes late, of 332 completed flights

Avg delay

80 min

Across delayed arrivals only, not all flights

Cancelled

0.60%

National rate is 1.89%

1 hour+ late

3.6%

National rate is 8.3%

These figures cover 334 flights between September 2025 and August 2026. The median arrival is 15 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.

Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.

Schedule

When UA 1524 flies

UA 1524 flies IAD to IAH without a single fixed slot. Its most common scheduled departure was 08:30, used on 148 of 334 flights, with 08:40 (82 flights) and 08:15 (57 flights) next.

Departs 08:30148 flights44.3%
Departs 08:4082 flights24.6%
Departs 08:1557 flights17.1%

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 08:30 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and UA 1524 runs 6 points better at 89.8%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.

Against the route

UA 1524 next to IAD to IAH

Every carrier on IAD to IAH combined arrived on time 84.7% of the time across 1,862 flights, so UA 1524 is 5 points ahead of it. Across its whole network United Airlines managed 78.8%, which this flight beats by 11 points.

UA 1524 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
UA 1524thin sample	334	89.8%	80 min	0.60%	A+
All United Airlines on IAD–IAH	1,862	84.7%	71 min	0.48%	B+
All carriers on IAD–IAH	1,862	84.7%	71 min	0.48%	B+
United Airlines, whole network	830,825	78.8%	73 min	1.02%	B

Across the year

UA 1524 quarter by quarter

Quarter by quarter UA 1524 held fairly steady: 86.6% in Oct–Dec 2025, 94.3% in Jan–Mar 2026, 84.6% in Apr–Jun 2026 and 91.9% in Jul–Sep 2026. A spread of 10 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202524 flights—
Oct–Dec 202567 flights86.6%
Jan–Mar 202690 flights94.3%
Apr–Jun 202691 flights84.6%
Jul–Sep 202662 flights91.9%

Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, UA 1524 ranged from 83.0% on Sunday to 93.6% on Friday. With about 48 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.

Arrival by arrival

How late UA 1524 runs when it is late

UA 1524 often beats the schedule: 168 of 332 completed flights, 51%, arrived 15 minutes or more early. The 34 late arrivals split 13 under half an hour, 9 between 30 and 60 minutes, and 12 an hour or more.

15+ min early168 flights50.6%
Within 15 min130 flights39.2%
15–29 min late13 flights3.9%
30–59 min late9 flights2.7%
1–2 hours late7 flights2.1%
2+ hours late5 flights1.5%

Scale runs 0% to 100%.

Share of 332 completed flights by arrival against schedule.

A late pushback is often recovered here: of 32 departures that left 15 minutes late or more, 13 still arrived on time. 15 flights left on time and still arrived late.

The worst days

Worst days for UA 1524

The latest arrival of the period was on 17 March 2026, 8 hours 57 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. Three of the five worst days fell in June 2026.

The latest arrivals of UA 1524 in the period
Date	Arrived late by	Largest filed cause
17 March 2026	8 hours 57 minutes	Late-arriving aircraft
31 January 2026	7 hours 3 minutes	Carrier
15 June 2026	2 hours 59 minutes	National Airspace System
14 June 2026	2 hours 23 minutes	National Airspace System
16 June 2026	2 hours 4 minutes	Carrier

Delay causes

Why UA 1524 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 2,711 reported delay minutes.

Carrier
40%
National Airspace System
36%
Late-arriving aircraft
22%
Extreme weather
3%

36% 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 972 minutes out of 2,711, against a national NAS share of 21%. The split is drawn from 2,711 delay minutes reported on UA 1524.

Cancellations are rare at 0.60%, 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

Badly late arrivals are rare here: only 3.6% land an hour or more behind schedule, against 8.3% 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 1,190 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.

UA 1524 is not only a IAD to IAH flight. It also flew IAH to LAS (251 flights, 89.2% 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. 334 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 1524
Also flown as	Flights	On time	Avg delay	Cancelled	Grade
IAH to LASthin sample	251	89.2%	75 min	0.00%	A+

What to do with this

Booking UA 1524

For a booking, UA 1524 has one of the better records a US domestic flight can show: 89.8% on time and 0.60% cancelled. That is a base rate, not a promise about any single 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, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures