Carrier route record
WNFAT→DEN
Southwest Airlines · Fresno to Denver
- Flights
- 359
- Period
- September 2025 to August 2026
- Share of route
- 25%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on FAT to DEN lands a B+, 4 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about 55 minutes on average. That rests on 359 flights, with a median arrival 8 minutes early.
The US average over the same twelve months is 77.3%, so there is little to separate Southwest on FAT to DEN from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
81.0%
Arrivals under 15 minutes late, of 358 completed flights
Avg delay
54 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.89%
Whole route
88.7%
Every carrier on FAT to DEN, 1,449 flights
These figures cover 359 flights between September 2025 and August 2026. The median arrival is 8 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 FAT to DEN
Southwest flew 359 of the 1,449 flights on FAT to DEN, about 25% of it. Its 81.0% on time is 8 points worse than the route as a whole, which runs 88.7%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from United at 91.5% to Southwest at 81.0%. 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 |
|---|---|---|---|---|---|
| United Airlinesthin sample | 344 | 91.5% | 95 min | 0.29% | A+ |
| SkyWest Airlines | 746 | 91.1% | 87 min | 0.00% | A+ |
| Southwest Airlines (this page)thin sample | 359 | 81.0% | 54 min | 0.00% | B+ |
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Departure window
When Southwest 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 359 flights.
There are not enough flights in each departure window to split Southwest's FAT to DEN record by time of day without the percentages moving on noise. The headline rate of 81.0% is the reliable figure here.
Across the year
Southwest on FAT to DEN through the year
June is the worst month at 63.3% on time, 25 points below December, the best at 87.9%. 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. December was the busiest month here, with 33 flights.
Across the week, Sunday is the strongest day at 88.5% on time and Friday the weakest at 71.2%, a spread of 17 points.
Arrival by arrival
How late Southwest on FAT to DEN runs when it is late
Southwest on FAT to DEN often beats the schedule: 91 of 358 completed flights, 25%, arrived 15 minutes or more early. The 68 late arrivals split 29 under half an hour, 20 between 30 and 60 minutes, and 19 an hour or more.
- 15+ min early91 flights25.4%
- Within 15 min199 flights55.6%
- 15–29 min late29 flights8.1%
- 30–59 min late20 flights5.6%
- 1–2 hours late13 flights3.6%
- 2+ hours late6 flights1.7%
Scale runs 0% to 100%.
Share of 358 completed flights by arrival against schedule.
16 of 76 late departures made up the time and arrived on time, 21% of them. 8 flights left on time and still arrived late.
The worst days
Worst days for Southwest on FAT to DEN
The latest arrival of the period was on 1 April 2026, 5 hours 22 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The five worst days are spread across April, February, January, July and December, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 1 April 2026 | 5 hours 22 minutes | Carrier |
| 17 February 2026 | 3 hours 28 minutes | National Airspace System |
| 20 January 2026 | 2 hours 37 minutes | Carrier |
| 8 July 2026 | 2 hours 33 minutes | National Airspace System |
| 1 December 2025 | 2 hours 20 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 3,675 reported delay minutes.
- 37%Late-arriving aircraft
- 35%National Airspace System
- 28%Carrier
37% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 3,675 reported delay minutes here, that single category outweighs weather by 37 to one. The split is drawn from 3,675 reported delay minutes.
35% 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 1,300 minutes out of 3,675, against a national NAS share of 21%.
Cancellations are rare at 0.00%, below the national 1.89% and low enough to earn the plus on the grade. Almost no flights are called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
5.3% 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 55 minutes, which a normal layover absorbs.
The 844 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 74.1% on time across 360 flights, 7 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 7 points of difference.
One caution: this is a thin sample. 359 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 FAT to DEN
Put together: treat all of this as provisional. 359 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 81.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 358 completed flights over 12 months sit behind that.
Related
Where to go next
- FAT to DEN, every carrier
- Southwest on DEN to FAT, the return leg
- United Airlines on FAT to DEN91.5%
- SkyWest Airlines on FAT to DEN91.1%
- Southwest Airlines network-wide record
- Denver International (DEN) delay statistics
- Why the first flight of the morning is statistically safest
- Worst months to fly in the US, ranked by the data
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.