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DelayAtlas

Flight number record

UA 1501

United Airlines · Houston to Tampa

Route
IAH → TPA
Departs
12:35
Flights
328
Period
July 2025 to June 2026
B+GRADE

Historical statistics for July 2025 to June 2026, not live status. For today’s UA 1501, check with United Airlines.

UA 1501 sits in the middle of the pack with a B+. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land about 55 minutes behind schedule. That rests on 328 flights, with a median arrival 7 minutes early.

Key figures

On time

75.4%

Arrivals under 15 minutes late, of 325 completed flights

Avg delay

55 min

Across delayed arrivals only, not all flights

Cancelled

0.61%

National rate is 1.81%

1 hour+ late

7.1%

National rate is 8.1%

These figures cover 328 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 1501 flies

UA 1501 flies IAH to TPA without a single fixed slot. Its most common scheduled departure was 12:35, used on 102 of 328 flights, with 12:40 (74 flights) and 12:50 (71 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

  • Departs 12:35102 flights31.1%
  • Departs 12:4074 flights22.6%
  • Departs 12:5071 flights21.6%

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 12:35 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.8%, and UA 1501 runs 3 points worse at 75.4%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

UA 1501 next to IAH to TPA

Every carrier on IAH to TPA combined arrived on time 81.6% of the time across 1,643 flights, so UA 1501 is 6 points behind it. United flew 1,363 flights on the same city pair under all its flight numbers, including this one, and those ran 83.6% on time. Across its whole network United Airlines managed 79.0%, which this flight trails by 4 points.

UA 1501 against its route and carrier
Compared withFlightsOn timeAvg delayCancelledGrade
UA 1501thin sample32875.4%55 min0.61%B+
All United Airlines on IAH–TPA1,36383.6%66 min0.37%B+
All carriers on IAH–TPA1,64381.6%73 min0.49%B+
United Airlines, whole network821,04179.0%72 min1.01%B

Across the year

UA 1501 quarter by quarter

UA 1501 did not run the same all year. Its best quarter was Jan–Mar 2026 at 79.2% on time and its weakest Apr–Jun 2026 at 67.0%, a swing of 12 points on roughly 82 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 202592 flights78.0%
  • Oct–Dec 202592 flights78.9%
  • Jan–Mar 202653 flights79.2%
  • Apr–Jun 202691 flights67.0%

Scale runs 60% to 85%. Rows with fewer than 30 flights show a dash.

By weekday, UA 1501 did best on Thursday at 84.8% on time and worst on Sunday at 61.7%. Each day rests on about 47 flights, so a gap of 23 points is worth noticing but could still narrow in another year.

On-time rate by day of the week72.3Mon82.2Tue80.4Wed84.8Thu72.3Fri74.5Sat61.7Sun
Monday: 72.3 percent on time. Tuesday: 82.2 percent on time. Wednesday: 80.4 percent on time. Thursday: 84.8 percent on time. Friday: 72.3 percent on time. Saturday: 74.5 percent on time. Sunday: 61.7 percent on time

Delay causes

Why UA 1501 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 4,379 reported delay minutes.

  • Late-arriving aircraft
    42%
  • National Airspace System
    24%
  • Carrier
    22%
  • Extreme weather
    12%

Extreme weather accounts for 12% 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 1.9 times the usual weather exposure. The split is drawn from 4,379 delay minutes reported on UA 1501.

Cancellations are rare at 0.61%, 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

7.1% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 55 minutes, which a normal layover absorbs.

The 787 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 TPA to EWR (41), FLL to EWR (37) and SAN to IAH (35), but none flew often enough under UA 1501 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to IAH to TPA only.

One caution: this is a thin sample. 328 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 1501

For a booking, UA 1501 is one of the weaker ways to fly IAH to TPA: 6 points below the route as a whole. If the schedule allows, compare it with the other departures listed on the route page before settling on this one.

Related

Where to go next

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.