Carrier route record

WNDEN→BZN

Southwest Airlines · Denver to Bozeman

Flights: 1,173
Period: July 2025 to June 2026
Share of route: 43%
Carriers: 3

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

Southwest on DEN to BZN sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.6%. The late ones land roughly 50 minutes behind schedule. That rests on 1,173 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 393 at 88.4% on time.

The national on-time rate over the same period is 77.6%, so Southwest on DEN to BZN runs 7 points behind the country as a whole. Across a thousand flights that is about 71 extra late arrivals.

On time

70.5%

Arrivals under 15 minutes late, of 1,168 completed flights

Avg delay

51 min

Across delayed arrivals only, not all flights

Cancelled

0.43%

National rate is 1.81%

Whole route

78.1%

Every carrier on DEN to BZN, 2,729 flights

These figures cover 1,173 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.

Carrier by carrier

Southwest against every carrier on DEN to BZN

Southwest flew 1,173 of the 2,729 flights on DEN to BZN, about 43% of it. Its 70.5% on time is 8 points worse than the route as a whole, which runs 78.1%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from SkyWest at 88.4% to Southwest at 70.5%.

The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 88.4% of the time; United Airlines manages 82.3%. Sample sizes sit next to every figure, because a two-point gap across 1,163 flights means less than a ten-point one.

On-time performance by carrier on DEN to BZN
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlines	393	88.4%	59 min	1.02%	A
United Airlines	1,163	82.3%	61 min	0.09%	B+
Southwest Airlines (this page)	1,173	70.5%	51 min	0.43%	C+

SkyWest leads United by 6 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Departure window

When Southwest runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 32 points, against 6 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am86 flights84.7%
8am–11am279 flights89.2%
11am–2pm226 flights71.1%
2pm–5pm186 flights60.5%
5pm–8pm57 flights64.9%
8pm–5am339 flights57.6%

Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 57.6% on time, against 89.2% for the 8am–11am 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 8pm–5am window is the busiest, with 339 flights scheduled in it.

Across the year

Southwest on DEN to BZN through the year

Darker means more delays. Figures are on-time percentages.October best, June worst

June is the worst month at 45.1% on time, 45 points below October, the best at 89.7%. 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 120 flights.

Across the week, Wednesday is the strongest day at 73.8% on time and Thursday the weakest at 64.7%. 9 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Southwest runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 55% of the 17,000 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.

Late-arriving aircraft
55%
Carrier
34%
National Airspace System
11%
Extreme weather
1%

55% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 17,000 reported delay minutes here, that single category outweighs weather by 55 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 17,182 reported delay minutes.

The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 89.2% on time here.

Cancellations are rare at 0.43%, 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 costs

6.8% 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 roughly 50 minutes, 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 is a different operation and performs like one: it runs 74.6% on time across 1,174 flights, 4 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 4 points of difference.

The sample behind these figures is 1,173 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 Southwest on DEN to BZN

Put together: the calendar is the biggest lever here, not the carrier or the hour. October runs 89.7% on time and June 45.1%, a swing of 45 points. If the dates move at all, move them out of June before you think about anything else. 1,168 completed flights over 12 months sit behind that.

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.

Key figures