Route reliability record
BHM→DEN
Birmingham to Denver
- Flights
- 1,192
- Period
- July 2025 to June 2026
- Distance
- 1,083 mi
- Carriers
- 3
This route lands a B+, 6 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 1,192 BHM to DEN flights, of which SkyWest Airlines flew 667 at 86.7% on time.
Best time to fly BHM to DEN: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 92.6% of the time and Wednesday flights 86.0%, against 83.2% for the route overall.
Set against the rest of the country, this route's record is 6 points better than the US average of 77.6%. That gap is worth roughly 56 fewer late arrivals for every thousand flights.
Key figures
On time
83.2%
Arrivals under 15 minutes late, of 1,186 completed flights
Avg delay
64 min
Across delayed arrivals only, not all flights
Cancelled
0.17%
National rate is 1.81%
Best carrier
SkyWest
86.7% on time across 667 flights
These figures cover 1,192 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.
Carrier by carrier
Which airline is most reliable on BHM to DEN
The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 86.7% of the time; Southwest Airlines manages 79.1%. Sample sizes sit next to every figure, because a two-point gap across 464 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlines | 667 | 86.7% | 76 min | 0.30% | A+ |
| Southwest Airlines | 464 | 79.1% | 52 min | 0.00% | B+ |
| United Airlinesthin sample | 61 | 77.0% | 70 min | 0.00% | B+ |
SkyWest leads Southwest by 8 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Flight by flight
Flights on BHM to DEN
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
Best ways to make this trip
The most reliable ways to fly Birmingham to Denver
Every airline on this route, ranked by how often a scheduled flight actually operated and arrived on time, with its best departure time and most punctual flight number. No nearby airport pair beat these.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. BHM → DENBirmingham to Denver | SkyWest Airlines | 86.4% | 86.7% | 0.30% | 8am–11am, Sun | OO 5295 08:00 |
| 2. BHM → DENBirmingham to Denver | Southwest Airlines | 79.1% | 79.1% | 0.00% | 5am–8am, Tue | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 44 points, against 8 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am189 flights92.6%
- 8am–11am491 flights89.0%
- 11am–2pm23 flights—
- 2pm–5pm389 flights79.9%
- 5pm–8pm100 flights49.0%
- 8pm–5am—
Scale runs 40% to 100%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 49.0% on time, against 92.6% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 8am–11am window is the busiest, with 491 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 24 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
June is the worst month at 69.8% on time, 24 points below February, the best at 94.0%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. May was the busiest month here, with 118 flights.
Across the week, Wednesday is the strongest day at 86.0% on time and Monday the weakest at 79.1%. 7 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
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 13,000 reported delay minutes.
- 40%Carrier
- 30%National Airspace System
- 28%Late-arriving aircraft
- 2%Extreme weather
The largest share of delay minutes, 40%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 5,101 of the 13,000 delay minutes reported here. The split is drawn from 12,695 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 92.6% on time here.
Cancellations are rare at 0.17%, 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 stage length
What a delay here actually costs
5.6% 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 an hour, which a normal layover absorbs.
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. 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 return leg is a different operation and performs like one: it runs 73.8% on time across 1,192 flights, 9 points below 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 9 points of difference.
The sample behind these figures is 1,192 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
Work out the risk of missing a connection in DEN after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 94.0% on time and June 69.8%, a swing of 24 points. If the dates move at all, move them out of June before you think about anything else. 1,186 completed flights over 12 months sit behind that.
Common questions
BHM to DEN questions
How often is BHM to DEN delayed?
About one flight in six arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 16.8% of the 1,192 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on BHM to DEN?
SkyWest Airlines leads at 86.7% on time across 667 flights. Southwest Airlines is at the other end on 79.1%, a gap of 8 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on BHM to DEN?
The 5am–8am departure window is the strongest at 92.6% on time. The 5pm–8pm window is the weakest at 49.0%, 44 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are June delays on BHM to DEN?
June is the weakest month at 69.8% on time, compared with 94.0% in February. Across the year that is 24 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- DEN to BHM — the return legseparate record
- Denver International (DEN) delay statistics
- SkyWest Airlines on BHM to DEN86.7%
- Southwest Airlines on BHM to DEN79.1%
- BHM to ATL, a related route88.3%
- PHX to DEN, a related route77.2%
- BHM to DFW, a related route78.6%
- SkyWest Airlines on-time record86.7%
- Southwest Airlines on-time record79.1%
- United Airlines on-time record77.0%
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
Direction matters. BHM to DEN and DEN to BHM are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.