Carrier route record
WNDEN→PIT
Southwest Airlines · Denver to Pittsburgh
- Flights
- 768
- Period
- September 2025 to August 2026
- Share of route
- 47%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on DEN to PIT draws a C+. About one flight in three arrives at least 15 minutes late, and the typical late arrival is about an hour behind schedule. Build slack into anything you connect to. That rests on 768 flights, with a median arrival 5 minutes late.
The national on-time rate over the same period is 77.3%, so Southwest on DEN to PIT runs 12 points behind the country as a whole. Across a thousand flights that is about 119 extra late arrivals.
Key figures
On time
65.4%
Arrivals under 15 minutes late, of 764 completed flights
Avg delay
57 min
Across delayed arrivals only, not all flights
Cancelled
0.52%
National rate is 1.89%
Whole route
74.1%
Every carrier on DEN to PIT, 1,622 flights
These figures cover 768 flights between September 2025 and August 2026. Beyond the headline rate, 12.0% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Carrier by carrier
Southwest against every carrier on DEN to PIT
Southwest flew 768 of the 1,622 flights on DEN to PIT, about 47% of it. Its 65.4% on time is 9 points worse than the route as a whole, which runs 74.1%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Frontier at 100.0% to Southwest at 65.4%. 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 |
|---|---|---|---|---|---|
| Frontier Airlinesthin sample | 35 | 100.0% | — | 0.00% | A+ |
| United Airlines | 819 | 81.2% | 58 min | 0.49% | B+ |
| Southwest Airlines (this page) | 768 | 65.4% | 57 min | 0.52% | 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 31 points, against half a point between the best and worst carrier.
- 5am–8am—
- 8am–11am272 flights79.3%
- 11am–2pm93 flights81.7%
- 2pm–5pm125 flights53.6%
- 5pm–8pm233 flights50.9%
- 8pm–5am45 flights55.6%
Scale runs 40% to 85%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 50.9% on time, against 81.7% for the 11am–2pm 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 272 flights scheduled in it.
Across the year
Southwest on DEN to PIT through the year
June is the worst month at 50.6% on time, 34 points below January, the best at 84.2%. 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 85 flights.
Across the week, Sunday is the strongest day at 72.0% on time and Monday the weakest at 59.3%, a spread of 13 points.
Arrival by arrival
How late Southwest on DEN to PIT runs when it is late
The 264 late arrivals split 91 under half an hour, 81 between 30 and 60 minutes, and 92 an hour or more.
- 15+ min early68 flights8.9%
- Within 15 min432 flights56.5%
- 15–29 min late91 flights11.9%
- 30–59 min late81 flights10.6%
- 1–2 hours late68 flights8.9%
- 2+ hours late24 flights3.1%
Scale runs 0% to 100%.
Share of 764 completed flights by arrival against schedule.
96 of 333 late departures made up the time and arrived on time, 29% of them. 27 flights left on time and still arrived late.
The worst days
Worst days for Southwest on DEN to PIT
The latest arrival of the period was on 13 August 2026, 5 hours behind schedule; most of its delay minutes were filed as a late-arriving aircraft. Four of the five worst days fell in August 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 13 August 2026 | 5 hours | Late-arriving aircraft |
| 22 August 2026 | 4 hours 51 minutes | Late-arriving aircraft |
| 24 August 2026 | 4 hours 19 minutes | Late-arriving aircraft |
| 28 July 2026 | 3 hours 57 minutes | Late-arriving aircraft |
| 9 August 2026 | 3 hours 48 minutes | Carrier |
Delay causes
Why Southwest runs late on this route
Late-arriving aircraft accounts for 56% of the 15,000 delay minutes carriers reported here, and the remaining four split what is left.
- 56%Late-arriving aircraft
- 31%Carrier
- 13%National Airspace System
- 1%Extreme weather
56% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 15,000 reported delay minutes here, that single category outweighs weather by 56 to one. The split is drawn from 15,135 reported delay minutes.
Cancellations are rare at 0.52%, 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
12.0% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
The 1,290 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 74.6% on time across 768 flights, 9 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 9 points of difference.
One caution: this is a thin sample. 768 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 DEN to PIT
Put together: treat all of this as provisional. 768 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 65.4% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 764 completed flights over 12 months sit behind that.
Related
Where to go next
- DEN to PIT, every carrier
- Southwest on PIT to DEN, the return leg
- United Airlines on DEN to PIT81.2%
- Southwest Airlines network-wide record
- Denver International (DEN) delay statistics
- Pittsburgh International (PIT) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
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.