Route reliability record

DEN→TPA

Denver to Tampa

Flights: 3,098
Period: July 2025 to June 2026
Distance: 1,506 mi
Carriers: 3

This route lands a B+, about a point worse than the national rate of 77.6%. About one flight in four arrive 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 3,098 flights, of which Frontier Airlines flew 603 at 81.6% on time.

Frontier Airlines is the most reliable of the three carriers covered here at 81.6% on time across 603 flights.

On time

76.6%

Arrivals under 15 minutes late, of 3,079 completed flights

Avg delay

63 min

Across delayed arrivals only, not all flights

Cancelled

0.32%

National rate is 1.81%

Best carrier

Frontier

81.6% on time across 603 flights

These figures cover 3,098 flights between July 2025 and June 2026. The median arrival is 5 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

Which airline is most reliable on DEN to TPA

The choice of carrier is not cosmetic here. Frontier Airlines arrives on time 81.6% of the time; Southwest Airlines manages 70.0%. Sample sizes sit next to every figure, because a two-point gap across 1,309 flights means less than a ten-point one.

On-time performance by carrier on DEN to TPA
Airline	Flights	On time	Avg delay	Cancelled	Grade
Frontier Airlines	603	81.6%	72 min	0.83%	B+
United Airlines	1,186	81.4%	67 min	0.17%	B+
Southwest Airlines	1,309	70.0%	58 min	0.23%	C+

Frontier leads Southwest by 12 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Departure window

The best time of day to leave

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 27 points, against 12 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am428 flights90.4%
8am–11am790 flights84.0%
11am–2pm320 flights69.8%
2pm–5pm531 flights73.4%
5pm–8pm666 flights63.3%
8pm–5am363 flights79.8%

Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 63.3% on time, against 90.4% 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 8am–11am window is the busiest, with 790 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 33 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.

Darker means more delays. Figures are on-time percentages.November best, July worst

July is the worst month at 57.7% on time, 33 points below November, the best at 90.5%. 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. March was the busiest month here, with 334 flights.

Across the week, Wednesday is the strongest day at 80.0% on time and Tuesday the weakest at 72.4%. 8 points is a smaller lever than departure hour, but it is free.

Delay causes

Why this route gets delayed

One category carries most of the weight here. Late-arriving aircraft accounts for 44% of the 45,000 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.

Late-arriving aircraft
44%
Carrier
36%
National Airspace System
19%
Extreme weather
1%
Security
0%

44% 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 45,000 reported delay minutes here, that single category outweighs weather by 31 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 45,019 reported delay minutes.

The largest share of delay minutes, 36%, 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 16,000 of the 45,000 delay minutes reported here.

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 actually costs

7.5% 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 are the about an hour kind, 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 81.2% on time across 3,099 flights, 5 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 5 points of difference.

The sample behind these figures is 3,098 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 this route

Put together: the calendar is the biggest lever here, not the carrier or the hour. November runs 90.5% on time and July 57.7%, a swing of 33 points. If the dates move at all, move them out of July before you think about anything else. 3,079 completed flights over 12 months sit behind that.

Common questions

DEN to TPA questions

How often is DEN to TPA delayed?

About one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 23.4% of the 3,098 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.

Which airline is most reliable on DEN to TPA?

Frontier Airlines leads at 81.6% on time across 603 flights. Southwest Airlines is at the other end on 70.0%, a gap of 12 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.

What time of day has the fewest delays on DEN to TPA?

The 5am–8am departure window is the strongest at 90.4% on time. The 5pm–8pm window is the weakest at 63.3%, 27 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.

How bad are July delays on DEN to TPA?

July is the weakest month at 57.7% on time, compared with 90.5% in November. Across the year that is 33 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Where to go next

Direction matters. DEN to TPA and TPA to DEN are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.

Key figures