Carrier route record
WNMTJ→DEN
Southwest Airlines · Montrose to Denver
- Flights
- 428
- Period
- September 2025 to August 2026
- Share of route
- 30%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on MTJ to DEN lands a B+, 4 points better than the national rate of 77.3%. Roughly one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 428 flights, with a median arrival 13 minutes early.
Set against the rest of the country, Southwest's MTJ to DEN record is 4 points better than the US average of 77.3%. That gap is worth roughly 42 fewer late arrivals for every thousand flights.
Key figures
On time
81.5%
Arrivals under 15 minutes late, of 427 completed flights
Avg delay
65 min
Across delayed arrivals only, not all flights
Cancelled
0.23%
National rate is 1.89%
Whole route
80.4%
Every carrier on MTJ to DEN, 1,423 flights
These figures cover 428 flights between September 2025 and August 2026. The median arrival is 13 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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Carrier by carrier
Southwest against every carrier on MTJ to DEN
Southwest flew 428 of the 1,423 flights on MTJ to DEN, about 30% of it. Its 81.5% on time is about level with the route as a whole at 80.4%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from Southwest at 81.5% to SkyWest at 74.3%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Southwest Airlines (this page) | 428 | 81.5% | 65 min | 0.23% | B+ |
| United Airlines | 894 | 80.5% | 92 min | 0.45% | B+ |
| SkyWest Airlinesthin sample | 101 | 74.3% | 78 min | 0.00% | C+ |
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 11 points, against half a point between the best and worst carrier.
- 5am–8am—
- 8am–11am185 flights79.9%
- 11am–2pm186 flights84.9%
- 2pm–5pm49 flights73.5%
- 5pm–8pm8 flights—
- 8pm–5am—
Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 11am–2pm slot at 84.9% on time, ahead of 2pm–5pm at 73.5%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 11am–2pm window is the busiest, with 186 flights scheduled in it.
Across the year
Southwest on MTJ to DEN through the year
August is the worst month at 35.5% on time, 61 points below July, the best at 96.8%. 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. March was the busiest month here, with 58 flights.
Across the week, Sunday is the strongest day at 87.1% on time and Tuesday the weakest at 73.6%, a spread of 14 points.
Arrival by arrival
How late Southwest on MTJ to DEN runs when it is late
Southwest on MTJ to DEN often beats the schedule: 192 of 427 completed flights, 45%, arrived 15 minutes or more early. The 79 late arrivals split 37 under half an hour, 19 between 30 and 60 minutes, and 23 an hour or more.
- 15+ min early192 flights45.0%
- Within 15 min156 flights36.5%
- 15–29 min late37 flights8.7%
- 30–59 min late19 flights4.4%
- 1–2 hours late12 flights2.8%
- 2+ hours late11 flights2.6%
Scale runs 0% to 100%.
Share of 427 completed flights by arrival against schedule.
18 of 72 late departures made up the time and arrived on time, 25% of them. In the other direction, 25 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 Southwest on MTJ to DEN
The latest arrival of the period was on 27 March 2026, 9 hours 3 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). Three of the five worst days fell in March 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 27 March 2026 | 9 hours 3 minutes | Carrier |
| 30 June 2026 | 4 hours 21 minutes | Carrier |
| 6 March 2026 | 4 hours 17 minutes | National Airspace System |
| 6 March 2026 | 3 hours 44 minutes | Late-arriving aircraft |
| 17 February 2026 | 3 hours 29 minutes | Late-arriving aircraft |
Delay causes
Why Southwest runs late on this route
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 5,093 reported delay minutes.
- 38%Late-arriving aircraft
- 32%National Airspace System
- 31%Carrier
38% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 5,093 reported delay minutes here, that single category outweighs weather by 38 to one. The split is drawn from 5,093 reported delay minutes.
Cancellations are rare at 0.23%, 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
5.4% 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 about an hour, which a normal layover absorbs.
At 197 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 11am–2pm window matters as much as it does.
The return leg is a different operation and performs like one: it runs 72.0% on time across 429 flights, 10 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 10 points of difference.
One caution: this is a thin sample. 428 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 Southwest on MTJ to DEN
Put together: treat all of this as provisional. 428 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 81.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 427 completed flights over 12 months sit behind that.
Related
Where to go next
- MTJ to DEN, every carrier
- Southwest on DEN to MTJ, the return leg
- United Airlines on MTJ to DEN80.5%
- SkyWest Airlines on MTJ to DEN74.3%
- Southwest Airlines network-wide record
- Denver International (DEN) delay statistics
- Flying to ski country: which routes into the mountains run on time
- Why the first flight of the morning is statistically safest
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.