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DelayAtlas

Carrier route record

WNTPADEN

Southwest Airlines · Tampa to Denver

Flights
1,309
Period
July 2025 to June 2026
Share of route
42%
Carriers
3
B+GRADE

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

Southwest on TPA to DEN lands a B+, about a point better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about 50 minutes on average. That is a workable record, not a spotless one. That rests on 1,309 flights. The strongest carrier on the route with a full sample, United Airlines, flew 1,186 at 84.5% on time.

The US average over the same twelve months is 77.6%, so there is little to separate Southwest on TPA 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

79.0%

Arrivals under 15 minutes late, of 1,299 completed flights

Avg delay

49 min

Across delayed arrivals only, not all flights

Cancelled

0.23%

National rate is 1.81%

Whole route

81.2%

Every carrier on TPA to DEN, 3,099 flights

These figures cover 1,309 flights between July 2025 and June 2026. The median arrival is 3 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.

Carrier by carrier

Southwest against every carrier on TPA to DEN

Southwest flew 1,309 of the 3,099 flights on TPA to DEN, about 42% of it. Its 79.0% on time is 2 points worse than the route as a whole, which runs 81.2%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from United at 84.5% to Southwest at 79.0%.

The two carriers here are closely matched: 5 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.

On-time performance by carrier on TPA to DEN
AirlineFlightsOn timeAvg delayCancelledGrade
United Airlines1,18684.5%67 min0.34%B+
Frontier Airlines60479.3%85 min0.83%B+
Southwest Airlines (this page)1,30979.0%49 min0.23%B+

No carrier stands out. United tops the table at 84.5%, 5 points clear of the bottom, which is inside the range this kind of sample moves year to year.

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 33 points, against 5 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am342 flights94.1%
  • 8am–11am337 flights84.0%
  • 11am–2pm115 flights87.6%
  • 2pm–5pm172 flights68.5%
  • 5pm–8pm296 flights61.0%
  • 8pm–5am47 flights63.8%

Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 61.0% on time, against 94.1% for the 5am–8am 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 5am–8am window is the busiest, with 342 flights scheduled in it.

Across the year

Southwest on TPA to DEN through the year

On-time rate by calendar month80J84F80M84A81M71J78J70A87S75O82N79D
Darker means more delays. Figures are on-time percentages.September best, August worst

August is the worst month at 69.9% on time, 17 points below September, the best at 87.2%. 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 146 flights.

Across the week, Tuesday is the strongest day at 82.4% on time and Saturday the weakest at 75.8%. 7 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week76.3Mon82.4Tue82.0Wed76.8Thu79.8Fri75.8Sat79.8Sun
Monday: 76.3 percent on time. Tuesday: 82.4 percent on time. Wednesday: 82.0 percent on time. Thursday: 76.8 percent on time. Friday: 79.8 percent on time. Saturday: 75.8 percent on time. Sunday: 79.8 percent on time

Delay causes

Why Southwest runs late on this route

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 13,000 reported delay minutes.

  • Late-arriving aircraft
    35%
  • National Airspace System
    32%
  • Carrier
    28%
  • Extreme weather
    4%
  • Security
    0%

35% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 13,000 reported delay minutes here, that single category outweighs weather by 8 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 13,446 reported delay minutes.

32% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 4,313 minutes out of 13,000, against a national NAS share of 21%.

Cancellations are rare at 0.23%, 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

5.5% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 50 minutes, which a normal layover absorbs.

At 1,506 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 70.0% on time across 1,309 flights, 9 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 9 points of difference.

The sample behind these figures is 1,309 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.

What to do with this

Booking Southwest on TPA to DEN

Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 87.2% on time and August 69.9%, a swing of 17 points. If the dates move at all, move them out of August before you think about anything else. 1,299 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.