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DelayAtlas

Carrier route record

WNDENRSW

Southwest Airlines · Denver to Fort Myers

Flights
315
Period
July 2025 to June 2026
Share of route
28%
Carriers
3
C+GRADE

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.

Southwest on DEN to RSW 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 315 flights, with a median arrival 5 minutes late.

The national on-time rate over the same period is 77.6%, so Southwest on DEN to RSW runs 11 points behind the country as a whole. Across a thousand flights that is about 108 extra late arrivals.

Key figures

On time

66.8%

Arrivals under 15 minutes late, of 313 completed flights

Avg delay

62 min

Across delayed arrivals only, not all flights

Cancelled

0.32%

National rate is 1.81%

Whole route

79.8%

Every carrier on DEN to RSW, 1,132 flights

These figures cover 315 flights between July 2025 and June 2026. Beyond the headline rate, 9.9% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Carrier by carrier

Southwest against every carrier on DEN to RSW

Southwest flew 315 of the 1,132 flights on DEN to RSW, about 28% of it. Its 66.8% on time is 13 points worse than the route as a whole, which runs 79.8%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from United at 85.3% to Southwest at 66.8%. 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.

On-time performance by carrier on DEN to RSW
AirlineFlightsOn timeAvg delayCancelledGrade
United Airlines75985.3%56 min0.00%A+
Frontier Airlinesthin sample5877.2%58 min1.72%B
Southwest Airlines (this page)thin sample31566.8%62 min0.32%C+

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 19 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am
  • 8am–11am40 flights69.2%
  • 11am–2pm143 flights74.8%
  • 2pm–5pm122 flights56.2%
  • 5pm–8pm10 flights
  • 8pm–5am

Scale runs 50% to 80%. Rows with fewer than 30 flights show a dash.

The best window here is not the first bank but the 11am–2pm slot at 74.8% on time, ahead of 2pm–5pm at 56.2%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 11am–2pm window is the busiest, with 143 flights scheduled in it.

Across the year

Southwest on DEN to RSW through the year

On-time rate by calendar month81JF59M74A58M57J58JASO74N70D
Darker means more delays. Figures are on-time percentages.January best, June worst

June is the worst month at 56.7% on time, 25 points below January, the best at 81.2%. 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. March was the busiest month here, with 35 flights.

Across the week, Tuesday is the strongest day at 75.0% on time and Sunday the weakest at 47.7%. 27 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week65.1Mon75.0Tue72.1Wed67.4Thu72.1Fri67.9Sat47.7Sun
Monday: 65.1 percent on time. Tuesday: 75.0 percent on time. Wednesday: 72.1 percent on time. Thursday: 67.4 percent on time. Friday: 72.1 percent on time. Saturday: 67.9 percent on time. Sunday: 47.7 percent on time

Delay causes

Why Southwest runs late on this route

One category carries most of the weight here. Carrier accounts for 49% of the 6,429 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

  • Carrier
    49%
  • Late-arriving aircraft
    30%
  • National Airspace System
    19%
  • Extreme weather
    2%

The largest share of delay minutes, 49%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 3,153 of the 6,429 delay minutes reported here. The split is drawn from 6,429 reported delay minutes.

Cancellations are rare at 0.32%, below the national 1.81% 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

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.9% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

At 1,607 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.

The return leg is a different operation and performs like one: it runs 73.9% on time across 315 flights, 7 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 7 points of difference.

One caution: this is a thin sample. 315 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 RSW

Put together: treat all of this as provisional. 315 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 66.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 313 completed flights over 12 months sit behind that.

Related

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.