Carrier route record
UABHM→DEN
United Airlines · Birmingham to Denver
- Flights
- 123
- Period
- September 2025 to August 2026
- Share of route
- 10%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with United Airlines.
United on BHM to DEN sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 5 points worse than the national rate of 77.3%. The late ones land a little over an hour behind schedule. That rests on 123 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 604 at 90.0% on time.
The national on-time rate over the same period is 77.3%, so United on BHM to DEN runs 5 points behind the country as a whole. Across a thousand flights that is about 52 extra late arrivals.
Key figures
On time
72.1%
Arrivals under 15 minutes late, of 122 completed flights
Avg delay
79 min
Across delayed arrivals only, not all flights
Cancelled
0.81%
National rate is 1.89%
Whole route
83.2%
Every carrier on BHM to DEN, 1,236 flights
These figures cover 123 flights between September 2025 and August 2026. Beyond the headline rate, 12.3% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
United against every carrier on BHM to DEN
United flew 123 of the 1,236 flights on BHM to DEN, about 10% of it. Its 72.1% on time is 11 points worse than the route as a whole, which runs 83.2%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from SkyWest at 90.0% to United at 72.1%.
The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 90.0% of the time; Southwest Airlines manages 77.8%. Sample sizes sit next to every figure, because a two-point gap across 509 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlines | 604 | 90.0% | 81 min | 0.33% | A+ |
| Southwest Airlines | 509 | 77.8% | 57 min | 0.00% | B+ |
| United Airlines (this page)thin sample | 123 | 72.1% | 79 min | 0.81% | C+ |
The spread between SkyWest and Southwest is 12 points, wide enough that it should decide the booking. On a hundred trips that is 12 more arrivals inside the on-time window.
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Departure window
When United runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 123 flights.
There are not enough flights in each departure window to split United's BHM to DEN record by time of day without the percentages moving on noise. The headline rate of 72.1% is the reliable figure here.
Across the year
United on BHM to DEN through the year
- Apr–Jun 202661 flights77.0%
- Jul–Sep 202662 flights67.2%
Scale runs 60% to 80%.
Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 72.1% on time across 123 flights.
Split by quarter, United on BHM to DEN logged 61 flights in Apr–Jun 2026 and 62 flights in Jul–Sep 2026. Fewer than three of those quarters carried the 30 completed flights this site needs before printing a rate, so the 72.1% annual figure is the one to use.
Arrival by arrival
How late United on BHM to DEN runs when it is late
United on BHM to DEN often beats the schedule: 33 of 122 completed flights, 27%, arrived 15 minutes or more early. The 34 late arrivals split 8 under half an hour, 11 between 30 and 60 minutes, and 15 an hour or more.
- 15+ min early33 flights27.0%
- Within 15 min55 flights45.1%
- 15–29 min late8 flights6.6%
- 30–59 min late11 flights9.0%
- 1–2 hours late7 flights5.7%
- 2+ hours late8 flights6.6%
Scale runs 0% to 100%.
Share of 122 completed flights by arrival against schedule.
7 of 29 late departures made up the time and arrived on time, 24% of them. In the other direction, 12 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at DEN.
The worst days
Worst days for United on BHM to DEN
The latest arrival of the period was on 13 August 2026, 4 hours 11 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. Three of the five worst days fell in August 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 13 August 2026 | 4 hours 11 minutes | National Airspace System |
| 14 August 2026 | 3 hours 45 minutes | National Airspace System |
| 15 August 2026 | 3 hours 43 minutes | National Airspace System |
| 17 May 2026 | 3 hours 1 minute | National Airspace System |
| 28 July 2026 | 2 hours 57 minutes | National Airspace System |
Delay causes
Why United runs late on this route
National Airspace System accounts for 62% of the 2,674 delay minutes carriers reported here, and the remaining four split what is left.
- 62%National Airspace System
- 22%Late-arriving aircraft
- 14%Carrier
- 2%Extreme weather
62% 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 1,655 minutes out of 2,674, against a national NAS share of 21%. The split is drawn from 2,674 reported delay minutes.
Cancellations are rare at 0.81%, 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 stage length
What a delay here costs
12.3% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
The 1,083 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.
The return leg is a different operation and performs like one: it runs 77.2% on time across 123 flights, 5 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 5 points of difference.
One caution: this is a thin sample. 123 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 United on BHM to DEN
Put together: treat all of this as provisional. 123 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 72.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 122 completed flights over 12 months sit behind that.
Related
Where to go next
- BHM to DEN, every carrier
- United on DEN to BHM, the return leg
- SkyWest Airlines on BHM to DEN90.0%
- Southwest Airlines on BHM to DEN77.8%
- United Airlines network-wide record
- Denver International (DEN) delay statistics
- Same route, different airline: where the carrier you pick matters most
- How often a connection fails at the major US hubs
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.