Route reliability record
BZN→DEN
Bozeman to Denver
- Flights
- 2,730
- Period
- July 2025 to June 2026
- Distance
- 524 mi
- Carriers
- 3
This route lands a B+, level with the national rate of 77.6%. Roughly one flight in four arrive 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 2,730 flights, of which United Airlines flew 1,163 at 78.8% on time.
United Airlines is the most reliable of the three carriers covered here at 78.8% on time across 1,163 flights.
Key figures
On time
76.9%
Arrivals under 15 minutes late, of 2,706 completed flights
Avg delay
65 min
Across delayed arrivals only, not all flights
Cancelled
0.48%
National rate is 1.81%
Best carrier
United
78.8% on time across 1,163 flights
These figures cover 2,730 flights between July 2025 and June 2026. The median arrival is 6 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 BZN to DEN
The three carriers here are closely matched: 4 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 1,163 | 78.8% | 73 min | 0.43% | B+ |
| SkyWest Airlines | 393 | 77.8% | 71 min | 1.27% | B |
| Southwest Airlines | 1,174 | 74.6% | 57 min | 0.26% | C+ |
No carrier stands out. United tops the table at 78.8%, 4 points clear of the bottom, which is inside the range this kind of sample moves year to year.
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 30 points, against 4 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am697 flights90.6%
- 8am–11am566 flights82.7%
- 11am–2pm196 flights81.5%
- 2pm–5pm1,026 flights67.1%
- 5pm–8pm245 flights61.0%
- 8pm–5am—
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 61.0% on time, against 90.6% 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 2pm–5pm window is the busiest, with 1,026 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.
July is the worst month at 62.3% on time, 24 points below January, the best at 86.1%. 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. July was the busiest month here, with 273 flights.
Across the week, Tuesday is the strongest day at 79.7% on time and Thursday the weakest at 72.5%. 7 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. National Airspace System accounts for 43% of the 41,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 43%National Airspace System
- 32%Late-arriving aircraft
- 20%Carrier
- 5%Extreme weather
43% 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 18,000 minutes out of 41,000, against a national NAS share of 21%. The split is drawn from 40,505 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 90.6% on time here.
Cancellations are rare at 0.48%, 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
7.7% 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 are the about an hour kind, which a normal layover absorbs.
The 524 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 runs 78.1% on time across 2,729 flights, within about a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 2,730 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.
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 86.1% on time and July 62.3%, a swing of 24 points. If the dates move at all, move them out of July before you think about anything else. 2,706 completed flights over 12 months sit behind that.
Common questions
BZN to DEN questions
How often is BZN to DEN delayed?
Roughly one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 23.1% of the 2,730 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on BZN to DEN?
United Airlines leads at 78.8% on time across 1,163 flights. Southwest Airlines is at the other end on 74.6%, a gap of 4 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 BZN to DEN?
The 5am–8am departure window is the strongest at 90.6% on time. The 5pm–8pm window is the weakest at 61.0%, 30 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 July delays on BZN to DEN?
July is the weakest month at 62.3% on time, compared with 86.1% in January. 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 BZN — the return legseparate record
- Denver International (DEN) delay statistics
- United Airlines on-time record78.8%
- SkyWest Airlines on-time record77.8%
- Southwest Airlines on-time record74.6%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. BZN to DEN and DEN to BZN are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.