Flight number record

UA 1575

United Airlines · Denver to Philadelphia

Route: DEN → PHL
Departs: 09:35
Flights: 301
Period: September 2025 to August 2026

Historical statistics for September 2025 to August 2026, not live status. For today’s UA 1575, check with United Airlines.

UA 1575 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 10 points better than the national rate of 77.3%. When something does go wrong the average delay runs about 55 minutes. That rests on 301 flights, with a median arrival 9 minutes early.

Set against the rest of the country, UA 1575's record is 10 points better than the US average of 77.3%. That gap is worth roughly 97 fewer late arrivals for every thousand flights.

On time

87.0%

Arrivals under 15 minutes late, of 300 completed flights

Avg delay

55 min

Across delayed arrivals only, not all flights

Cancelled

0.33%

National rate is 1.89%

1 hour+ late

3.3%

National rate is 8.3%

These figures cover 301 flights between September 2025 and August 2026. The median arrival is 9 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.

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Schedule

When UA 1575 flies

UA 1575 flies DEN to PHL without a single fixed slot. Its most common scheduled departure was 09:35, used on 82 of 301 flights, with 10:15 (60 flights) and 10:10 (53 flights) next.

Departs 09:3582 flights27.2%
Departs 10:1560 flights19.9%
Departs 10:1053 flights17.6%

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 09:35 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and UA 1575 runs 3 points better at 87.0%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

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Against the route

UA 1575 next to DEN to PHL

Every carrier on DEN to PHL combined arrived on time 72.8% of the time across 3,056 flights, so UA 1575 is 14 points ahead of it. United flew 952 flights on the same city pair under all its flight numbers, including this one, and those ran 79.0% on time. Across its whole network United Airlines managed 78.8%, which this flight beats by 8 points.

UA 1575 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
UA 1575thin sample	301	87.0%	55 min	0.33%	A+
All United Airlines on DEN–PHL	952	79.0%	71 min	0.53%	B+
All carriers on DEN–PHL	3,056	72.8%	79 min	1.44%	C
United Airlines, whole network	830,825	78.8%	73 min	1.02%	B

Across the year

UA 1575 quarter by quarter

UA 1575 did not run the same all year. Its best quarter was Apr–Jun 2026 at 92.3% on time and its weakest Jul–Sep 2026 at 80.6%, a swing of 12 points on roughly 75 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 20256 flights—
Oct–Dec 202578 flights85.9%
Jan–Mar 202664 flights87.3%
Apr–Jun 202691 flights92.3%
Jul–Sep 202662 flights80.6%

Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, UA 1575 ranged from 79.1% on Thursday to 90.7% on Monday. With about 43 flights behind each day, a spread of 12 points is inside normal variation, so the day you fly is not worth changing for this flight.

Arrival by arrival

How late UA 1575 runs when it is late

UA 1575 often beats the schedule: 99 of 300 completed flights, 33%, arrived 15 minutes or more early. The 39 late arrivals split 17 under half an hour, 12 between 30 and 60 minutes, and 10 an hour or more.

15+ min early99 flights33.0%
Within 15 min162 flights54.0%
15–29 min late17 flights5.7%
30–59 min late12 flights4.0%
1–2 hours late5 flights1.7%
2+ hours late5 flights1.7%

Scale runs 0% to 100%.

Share of 300 completed flights by arrival against schedule.

9 of 34 late departures made up the time and arrived on time, 26% of them. 14 flights left on time and still arrived late.

The worst days

Worst days for UA 1575

The latest arrival of the period was on 23 August 2026, 4 hours 22 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on four of the five worst days.

The latest arrivals of UA 1575 in the period
Date	Arrived late by	Largest filed cause
23 August 2026	4 hours 22 minutes	Late-arriving aircraft
27 August 2026	3 hours 31 minutes	National Airspace System
24 November 2025	2 hours 29 minutes	Late-arriving aircraft
10 December 2025	2 hours 17 minutes	Late-arriving aircraft
30 November 2025	2 hours	Late-arriving aircraft

Delay causes

Why UA 1575 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 2,132 reported delay minutes.

National Airspace System
38%
Late-arriving aircraft
37%
Carrier
26%

37% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 2,132 reported delay minutes here, that single category outweighs weather by 37 to one. The split is drawn from 2,132 delay minutes reported on UA 1575.

Cancellations are rare at 0.33%, 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 3.3% 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.

At 1,558 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 1575 is not only a DEN to PHL flight. It also flew PHL to SFO (258 flights, 56.0% 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. 301 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 1575
Also flown as	Flights	On time	Avg delay	Cancelled	Grade
PHL to SFOthin sample	258	56.0%	110 min	0.39%	D+

What to do with this

Booking UA 1575

For a booking, UA 1575 has one of the better records a US domestic flight can show: 87.0% on time and 0.33% 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