Carrier route record
WNDEN→CMH
Southwest Airlines · Denver to Columbus
- Flights
- 923
- Period
- September 2025 to August 2026
- Share of route
- 52%
- 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 CMH draws a D+. About one flight in three arrives at least 15 minutes late, and the typical late arrival is roughly 55 minutes behind schedule. Build slack into anything you connect to. That rests on 923 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 CMH runs 13 points behind the country as a whole. Across a thousand flights that is about 134 extra late arrivals.
Key figures
On time
63.9%
Arrivals under 15 minutes late, of 911 completed flights
Avg delay
53 min
Across delayed arrivals only, not all flights
Cancelled
0.87%
National rate is 1.89%
Whole route
72.9%
Every carrier on DEN to CMH, 1,776 flights
These figures cover 923 flights between September 2025 and August 2026. Beyond the headline rate, 10.2% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Southwest against every carrier on DEN to CMH
Southwest flew 923 of the 1,776 flights on DEN to CMH, most of the route. Its 63.9% on time is 9 points worse than the route as a whole, which runs 72.9%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from United at 83.1% to Southwest at 63.9%. 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 Airlines | 728 | 83.1% | 65 min | 0.69% | B+ |
| Frontier Airlinesthin sample | 125 | 80.8% | 91 min | 0.00% | B+ |
| Southwest Airlines (this page) | 923 | 63.9% | 53 min | 0.87% | D+ |
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 24 points, against half a point between the best and worst carrier.
- 5am–8am14 flights—
- 8am–11am226 flights76.4%
- 11am–2pm152 flights73.5%
- 2pm–5pm210 flights58.7%
- 5pm–8pm283 flights52.2%
- 8pm–5am38 flights59.5%
Scale runs 45% to 80%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 52.2% on time, against 76.4% 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 5pm–8pm window is the busiest, with 283 flights scheduled in it.
Across the year
Southwest on DEN to CMH through the year
June is the worst month at 44.0% on time, 42 points below January, the best at 85.5%. 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 89 flights.
Across the week, Saturday is the strongest day at 71.8% on time and Sunday the weakest at 56.9%, a spread of 15 points.
Arrival by arrival
How late Southwest on DEN to CMH runs when it is late
The 329 late arrivals split 139 under half an hour, 97 between 30 and 60 minutes, and 93 an hour or more.
- 15+ min early75 flights8.2%
- Within 15 min507 flights55.7%
- 15–29 min late139 flights15.3%
- 30–59 min late97 flights10.6%
- 1–2 hours late64 flights7.0%
- 2+ hours late29 flights3.2%
Scale runs 0% to 100%.
Share of 911 completed flights by arrival against schedule.
77 of 359 late departures made up the time and arrived on time, 21% of them. In the other direction, 47 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 CMH.
The worst days
Worst days for Southwest on DEN to CMH
The latest arrival of the period was on 21 September 2025, 4 hours 2 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 August 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 21 September 2025 | 4 hours 2 minutes | Carrier |
| 11 August 2026 | 4 hours 2 minutes | Carrier |
| 13 August 2026 | 3 hours 38 minutes | Late-arriving aircraft |
| 9 June 2026 | 3 hours 36 minutes | Late-arriving aircraft |
| 3 August 2026 | 3 hours 30 minutes | Late-arriving aircraft |
Delay causes
Why Southwest runs late on this route
Late-arriving aircraft accounts for 57% of the 17,000 delay minutes carriers reported here, and the remaining four split what is left.
- 57%Late-arriving aircraft
- 30%Carrier
- 12%National Airspace System
- 0%Security
- 0%Extreme weather
57% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 17,000 reported delay minutes here, that single category outweighs weather by 57 to one. The split is drawn from 17,365 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 76.4% on time here.
Cancellations are rare at 0.87%, 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
10.2% 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 1,154 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 78.8% on time across 923 flights, 15 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 15 points of difference.
One caution: this is a thin sample. 923 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 CMH
Put together: treat all of this as provisional. 923 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 63.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 911 completed flights over 12 months sit behind that.
Related
Where to go next
- DEN to CMH, every carrier
- Southwest on CMH to DEN, the return leg
- United Airlines on DEN to CMH83.1%
- Frontier Airlines on DEN to CMH80.8%
- Southwest Airlines network-wide record
- Denver International (DEN) delay statistics
- John Glenn Columbus International (CMH) delay statistics
- Why the first flight of the morning is statistically safest
- How often a connection fails at the major US hubs
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.