Carrier route record
WNDEN→CLE
Southwest Airlines · Denver to Cleveland
- Flights
- 610
- Period
- September 2025 to August 2026
- Share of route
- 33%
- 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 CLE draws a D+. Roughly 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 610 flights, with a median arrival 6 minutes late.
The national on-time rate over the same period is 77.3%, so Southwest on DEN to CLE runs 16 points behind the country as a whole. Across a thousand flights that is about 159 extra late arrivals.
Key figures
On time
61.4%
Arrivals under 15 minutes late, of 606 completed flights
Avg delay
53 min
Across delayed arrivals only, not all flights
Cancelled
0.49%
National rate is 1.89%
Whole route
75.9%
Every carrier on DEN to CLE, 1,847 flights
These figures cover 610 flights between September 2025 and August 2026. Beyond the headline rate, 10.1% 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 CLE
Southwest flew 610 of the 1,847 flights on DEN to CLE, about 33% of it. Its 61.4% on time is 15 points worse than the route as a whole, which runs 75.9%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Frontier at 85.3% to Southwest at 61.4%. 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 | 298 | 85.3% | 62 min | 1.01% | A |
| United Airlines | 939 | 82.3% | 70 min | 0.00% | B+ |
| Southwest Airlines (this page) | 610 | 61.4% | 53 min | 0.49% | 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 39 points, against half a point between the best and worst carrier.
- 5am–8am—
- 8am–11am175 flights79.4%
- 11am–2pm150 flights75.3%
- 2pm–5pm10 flights—
- 5pm–8pm243 flights40.2%
- 8pm–5am32 flights56.2%
Scale runs 30% to 85%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 40.2% on time, against 79.4% 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 243 flights scheduled in it.
Across the year
Southwest on DEN to CLE through the year
November is the best month on the calendar at 84.8% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. July was the busiest month here, with 62 flights.
Across the week, Tuesday is the strongest day at 71.8% on time and Monday the weakest at 48.4%, a spread of 23 points.
Arrival by arrival
How late Southwest on DEN to CLE runs when it is late
The 234 late arrivals split 79 under half an hour, 94 between 30 and 60 minutes, and 61 an hour or more.
- 15+ min early31 flights5.1%
- Within 15 min341 flights56.3%
- 15–29 min late79 flights13.0%
- 30–59 min late94 flights15.5%
- 1–2 hours late40 flights6.6%
- 2+ hours late21 flights3.5%
Scale runs 0% to 100%.
Share of 606 completed flights by arrival against schedule.
73 of 278 late departures made up the time and arrived on time, 26% of them. 29 flights left on time and still arrived late.
The worst days
Worst days for Southwest on DEN to CLE
The latest arrival of the period was on 27 July 2026, 4 hours 26 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on five of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 27 July 2026 | 4 hours 26 minutes | Late-arriving aircraft |
| 22 August 2026 | 3 hours 52 minutes | Late-arriving aircraft |
| 19 December 2025 | 3 hours 37 minutes | Late-arriving aircraft |
| 6 March 2026 | 3 hours 17 minutes | Late-arriving aircraft |
| 13 August 2026 | 3 hours 6 minutes | Late-arriving aircraft |
Delay causes
Why Southwest runs late on this route
Late-arriving aircraft accounts for 54% of the 12,000 delay minutes carriers reported here, and the remaining four split what is left.
- 54%Late-arriving aircraft
- 32%Carrier
- 14%National Airspace System
- 0%Extreme weather
54% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 12,000 reported delay minutes here, that single category outweighs weather by 54 to one. The split is drawn from 12,425 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 79.4% on time here.
Cancellations are rare at 0.49%, 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
10.1% 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 1,201 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 76.9% on time across 609 flights, 16 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 16 points of difference.
One caution: this is a thin sample. 610 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 CLE
Put together: treat all of this as provisional. 610 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 61.4% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 606 completed flights over 12 months sit behind that.
Related
Where to go next
- DEN to CLE, every carrier
- Southwest on CLE to DEN, the return leg
- Frontier Airlines on DEN to CLE85.3%
- United Airlines on DEN to CLE82.3%
- Southwest Airlines network-wide record
- Denver International (DEN) delay statistics
- Cleveland Hopkins International (CLE) 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.