Flight number record

UA 1505

United Airlines · Seattle to Denver

Route: SEA → DEN
Departs: 08:40
Flights: 314
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s UA 1505, check with United Airlines.

UA 1505 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 close to two hours. That rests on 314 flights, with a median arrival 12 minutes early.

Set against the rest of the country, UA 1505'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 311 completed flights

Avg delay

118 min

Across delayed arrivals only, not all flights

Cancelled

0.96%

National rate is 1.81%

1 hour+ late

4.8%

National rate is 8.1%

These figures cover 314 flights between July 2025 and June 2026. The median arrival is 12 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 1505 flies

UA 1505 flies SEA to DEN without a single fixed slot. Its most common scheduled departure was 08:40, used on 53 of 314 flights, with 08:45 (35 flights) and 08:36 (35 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 08:4053 flights16.9%
Departs 08:4535 flights11.1%
Departs 08:3635 flights11.1%

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 08:40 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and UA 1505 runs 7 points better 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 1505 next to SEA to DEN

Every carrier on SEA to DEN combined arrived on time 77.8% of the time across 6,317 flights, so UA 1505 is 13 points ahead of it. United flew 1,905 flights on the same city pair under all its flight numbers, including this one, and those ran 87.5% on time. Across its whole network United Airlines managed 79.0%, which this flight beats by 12 points.

UA 1505 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
UA 1505thin sample	314	91.0%	118 min	0.96%	A+
All United Airlines on SEA–DEN	1,905	87.5%	73 min	0.84%	A+
All carriers on SEA–DEN	6,317	77.8%	58 min	0.85%	B+
United Airlines, whole network	821,041	79.0%	72 min	1.01%	B

Across the year

UA 1505 quarter by quarter

Quarter by quarter UA 1505 held fairly steady: 93.0% in Jul–Sep 2025, 93.3% in Oct–Dec 2025, 85.2% in Jan–Mar 2026 and 93.3% in Apr–Jun 2026. A spread of 8 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202543 flights93.0%
Oct–Dec 202590 flights93.3%
Jan–Mar 202690 flights85.2%
Apr–Jun 202691 flights93.3%

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

By weekday, UA 1505 ranged from 87.0% on Tuesday to 97.7% on Thursday. With about 45 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 1505 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 3,296 reported delay minutes.

Carrier
37%
Late-arriving aircraft
32%
National Airspace System
16%
Extreme weather
15%

Extreme weather accounts for 15% 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 2.4 times the usual weather exposure. The split is drawn from 3,296 delay minutes reported on UA 1505.

Cancellations sit at 0.96% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and routes

What a delay on this flight costs

Badly late arrivals are rare here: only 4.8% 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 1,024 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.

UA 1505 is not only a SEA to DEN flight. It also flew DEN to EWR (307 flights, 70.0% 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. 314 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 1505
Also flown as	Flights	On time	Avg delay	Cancelled	Grade
DEN to EWRthin sample	307	70.0%	92 min	1.95%	C

What to do with this

Booking UA 1505

For a booking, UA 1505 has one of the better records a US domestic flight can show: 91.0% on time and 0.96% 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