Carrier route record
WNCMH→DEN
Southwest Airlines · Columbus to Denver
- 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 CMH to DEN lands a B+, 2 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 a little over an hour on average. That rests on 923 flights, with a median arrival 4 minutes early.
The US average over the same twelve months is 77.3%, so there is little to separate Southwest on CMH 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
78.8%
Arrivals under 15 minutes late, of 915 completed flights
Avg delay
68 min
Across delayed arrivals only, not all flights
Cancelled
0.54%
National rate is 1.89%
Whole route
79.4%
Every carrier on CMH to DEN, 1,776 flights
These figures cover 923 flights between September 2025 and August 2026. The median arrival is 4 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 CMH to DEN
Southwest flew 923 of the 1,776 flights on CMH to DEN, most of the route. Its 78.8% on time is about level with the route as a whole at 79.4%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from United at 81.6% to Frontier at 71.0%. 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 Airlines | 728 | 81.6% | 72 min | 0.82% | B+ |
| Southwest Airlines (this page) | 923 | 78.8% | 68 min | 0.54% | B+ |
| Frontier Airlinesthin sample | 125 | 71.0% | 77 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 34 points, against half a point between the best and worst carrier.
- 5am–8am360 flights93.6%
- 8am–11am16 flights—
- 11am–2pm122 flights79.3%
- 2pm–5pm71 flights59.4%
- 5pm–8pm289 flights66.9%
- 8pm–5am65 flights70.8%
Scale runs 50% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 93.6% of the time, against 59.4% for the afternoon window. That is 34 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 360 flights scheduled in it.
Across the year
Southwest on CMH to DEN through the year
December is the weak month at 57.3% on time, against 89.5% in April. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. July was the busiest month here, with 89 flights.
Across the week, Saturday is the strongest day at 85.4% on time and Sunday the weakest at 73.2%, a spread of 12 points.
Arrival by arrival
How late Southwest on CMH to DEN runs when it is late
The 194 late arrivals split 75 under half an hour, 51 between 30 and 60 minutes, and 68 an hour or more.
- 15+ min early194 flights21.2%
- Within 15 min527 flights57.6%
- 15–29 min late75 flights8.2%
- 30–59 min late51 flights5.6%
- 1–2 hours late34 flights3.7%
- 2+ hours late34 flights3.7%
Scale runs 0% to 100%.
Share of 915 completed flights by arrival against schedule.
65 of 222 late departures made up the time and arrived on time, 29% of them. 37 flights left on time and still arrived late.
The worst days
Worst days for Southwest on CMH to DEN
The latest arrival of the period was on 17 February 2026, 7 hours 14 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 17 February 2026 | 7 hours 14 minutes | Carrier |
| 11 November 2025 | 5 hours 51 minutes | Carrier |
| 15 July 2026 | 5 hours 10 minutes | Carrier |
| 14 August 2026 | 5 hours 2 minutes | National Airspace System |
| 12 June 2026 | 4 hours 55 minutes | Late-arriving aircraft |
Delay causes
Why Southwest runs late on this route
Late-arriving aircraft accounts for 45% of the 13,000 delay minutes carriers reported here, and the remaining four split what is left.
- 45%Late-arriving aircraft
- 26%National Airspace System
- 25%Carrier
- 4%Extreme weather
- 0%Security
45% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 13,000 reported delay minutes here, that single category outweighs weather by 11 to one. The split is drawn from 13,213 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 93.6% on time here.
Cancellations are rare at 0.54%, 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
7.4% 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 a little over an hour, which a normal layover absorbs.
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 63.9% on time across 923 flights, 15 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 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 CMH to DEN
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 78.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 915 completed flights over 12 months sit behind that.
Related
Where to go next
- CMH to DEN, every carrier
- Southwest on DEN to CMH, the return leg
- United Airlines on CMH to DEN81.6%
- Frontier Airlines on CMH to DEN71.0%
- Southwest Airlines network-wide record
- John Glenn Columbus International (CMH) delay statistics
- Denver International (DEN) 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.