Flight number record

UA 2135

United Airlines · Seattle to Houston

Route: SEA → IAH
Departs: 07:10
Flights: 359
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s UA 2135, check with United Airlines.

UA 2135 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 77.6%. When something does go wrong the average delay runs an hour and a half. That rests on 359 flights, with a median arrival 14 minutes early.

Set against the rest of the country, UA 2135's record is 13 points better than the US average of 77.6%. That gap is worth roughly 134 fewer late arrivals for every thousand flights.

On time

91.0%

Arrivals under 15 minutes late, of 355 completed flights

Avg delay

87 min

Across delayed arrivals only, not all flights

Cancelled

0.56%

National rate is 1.81%

1 hour+ late

2.5%

National rate is 8.1%

These figures cover 359 flights between July 2025 and June 2026. The median arrival is 14 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 2135 flies

UA 2135 flies SEA to IAH without a single fixed slot. Its most common scheduled departure was 07:10, used on 134 of 359 flights, with 07:00 (66 flights) and 06:45 (63 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 07:10134 flights37.3%
Departs 07:0066 flights18.4%
Departs 06:4563 flights17.5%

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 07:10 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and UA 2135 runs level with that at 91.0%. 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 2135 next to SEA to IAH

Every carrier on SEA to IAH combined arrived on time 80.3% of the time across 2,095 flights, so UA 2135 is 11 points ahead of it. United flew 1,243 flights on the same city pair under all its flight numbers, including this one, and those ran 84.5% on time. Across its whole network United Airlines managed 79.0%, which this flight beats by 12 points.

UA 2135 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
UA 2135thin sample	359	91.0%	87 min	0.56%	A+
All United Airlines on SEA–IAH	1,243	84.5%	70 min	0.56%	B+
All carriers on SEA–IAH	2,095	80.3%	56 min	0.62%	B+
United Airlines, whole network	821,041	79.0%	72 min	1.01%	B

Across the year

UA 2135 quarter by quarter

Quarter by quarter UA 2135 held fairly steady: 86.9% in Jul–Sep 2025, 91.3% in Oct–Dec 2025, 96.6% in Jan–Mar 2026 and 89.0% in Apr–Jun 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 202586 flights86.9%
Oct–Dec 202592 flights91.3%
Jan–Mar 202690 flights96.6%
Apr–Jun 202691 flights89.0%

Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, UA 2135 did best on Sunday at 98.0% on time and worst on Friday at 84.6%. Each day rests on about 51 flights, so a gap of 13 points is worth noticing but could still narrow in another year.

Delay causes

Why UA 2135 runs late

One category carries most of the weight here. Carrier accounts for 65% of the 2,785 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.

Carrier
65%
National Airspace System
18%
Late-arriving aircraft
17%

The largest share of delay minutes, 65%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 1,813 of the 2,785 delay minutes reported here. The split is drawn from 2,785 delay minutes reported on UA 2135.

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

Badly late arrivals are rare here: only 2.5% 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.

At 1,874 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.

The same number turns up on five other city pairs in the data, including IAH to FLL (165), IAH to ORD (158) and ORD to DCA (68), but none flew often enough under UA 2135 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SEA to IAH only.

One caution: this is a thin sample. 359 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 2135

For a booking, UA 2135 has one of the better records a US domestic flight can show: 91.0% on time and 0.56% 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures