Flight number record
UA 539
United Airlines · Dallas-Fort Worth to Houston
- Route
- DFW → IAH
- Departs
- 11:59
- Flights
- 257
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 539, check with United Airlines.
UA 539 earns a B. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.3%. When something does go wrong the average delay runs an hour and a half. That rests on 257 flights, with a median arrival 10 minutes early.
Set against the rest of the country, UA 539's record is 8 points better than the US average of 77.3%. That gap is worth roughly 76 fewer late arrivals for every thousand flights.
Key figures
On time
84.9%
Arrivals under 15 minutes late, of 251 completed flights
Avg delay
96 min
Across delayed arrivals only, not all flights
Cancelled
1.56%
National rate is 1.89%
1 hour+ late
6.0%
National rate is 8.3%
These figures cover 257 flights between September 2025 and August 2026. The median arrival is 10 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 539 flies
UA 539 flies DFW to IAH without a single fixed slot. Its most common scheduled departure was 11:59, used on 65 of 257 flights, with 12:00 (48 flights) and 12:05 (46 flights) next.
- Departs 11:5965 flights25.3%
- Departs 12:0048 flights18.7%
- Departs 12:0546 flights17.9%
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 11:59 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.3%, and UA 539 runs 7 points better at 84.9%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
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Against the route
UA 539 next to DFW to IAH
Every carrier on DFW to IAH combined arrived on time 70.7% of the time across 5,800 flights, so UA 539 is 14 points ahead of it. United flew 2,457 flights on the same city pair under all its flight numbers, including this one, and those ran 79.1% on time. Across its whole network United Airlines managed 78.8%, which this flight beats by 6 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 539thin sample | 257 | 84.9% | 96 min | 1.56% | B |
| All United Airlines on DFW–IAH | 2,457 | 79.1% | 81 min | 1.71% | B |
| All carriers on DFW–IAH | 5,800 | 70.7% | 79 min | 2.43% | C |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 539 quarter by quarter
UA 539 did not run the same all year. Its best quarter was Jul–Sep 2026 at 96.0% on time and its weakest Apr–Jun 2026 at 79.5%, a swing of 17 points on roughly 64 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.
- Oct–Dec 202542 flights81.6%
- Jan–Mar 202680 flights85.0%
- Apr–Jun 202683 flights79.5%
- Jul–Sep 202652 flights96.0%
Scale runs 70% to 100%.
By weekday, UA 539 did best on Tuesday at 92.5% on time and worst on Monday at 75.6%. Each day rests on about 37 flights, so a gap of 17 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late UA 539 runs when it is late
UA 539 often beats the schedule: 100 of 251 completed flights, 40%, arrived 15 minutes or more early. The 38 late arrivals split 14 under half an hour, 9 between 30 and 60 minutes, and 15 an hour or more.
- 15+ min early100 flights39.8%
- Within 15 min113 flights45.0%
- 15–29 min late14 flights5.6%
- 30–59 min late9 flights3.6%
- 1–2 hours late5 flights2.0%
- 2+ hours late10 flights4.0%
Scale runs 0% to 100%.
Share of 251 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 31 departures that left 15 minutes late or more, only 3 made it up before arrival. 10 flights left on time and still arrived late.
The worst days
Worst days for UA 539
The latest arrival of the period was on 7 March 2026, 10 hours 59 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The five worst days are spread across March, June, February and November, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 7 March 2026 | 10 hours 59 minutes | Carrier |
| 19 June 2026 | 6 hours 51 minutes | Extreme weather |
| 16 March 2026 | 5 hours 23 minutes | National Airspace System |
| 14 February 2026 | 4 hours 8 minutes | Carrier |
| 24 November 2025 | 3 hours 44 minutes | Late-arriving aircraft |
Delay causes
Why UA 539 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 3,635 reported delay minutes.
- 34%National Airspace System
- 33%Late-arriving aircraft
- 26%Carrier
- 7%Extreme weather
34% 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 1,243 minutes out of 3,635, against a national NAS share of 21%. The split is drawn from 3,635 delay minutes reported on UA 539.
Cancellations sit at 1.56% against a national 1.89%, which is ordinary. Diversions add another 0.78%.
Connections and routes
What a delay on this flight costs
6.0% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last an hour and a half, which a normal layover absorbs.
The same number turns up on ten other city pairs in the data, including ORD to DFW (243), FLL to SFO (31) and IAH to LAS (28), but none flew often enough under UA 539 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to DFW to IAH only.
One caution: this is a thin sample. 257 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 539
For a booking, read UA 539 as 84.9% on time with 1.56% cancelled over 257 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- DFW to IAH, every carrier and departure
- IAH to DFW, the return direction
- United Airlines 2260 on the same route94.9%
- United Airlines 2670 on the same route74.3%
- United Airlines 1609 on the same route62.9%
- United Airlines 2682 on the same route69.1%
- Dallas/Fort Worth International (DFW) delay statistics
- George Bush Intercontinental (IAH) delay statistics
- United Airlines on-time record
- Every United Airlines flight number with a record
- The most and least reliable flight numbers in the US
- Why the first flight of the morning is statistically safest
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 ; recomputed monthly. How this data is collected.