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DelayAtlas

Route reliability record

IADTPA

Washington to Tampa

Flights
1,366
Period
July 2025 to June 2026
Distance
811 mi
Carriers
2
B+GRADE

This route lands a B+, 4 points 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 a little over an hour on average. That is a workable record, not a spotless one. That rests on 1,366 IAD to TPA flights, with a median arrival 8 minutes early.

Best time to fly IAD to TPA: a 8am–11am departure, ideally on a Tuesday. Flights in that window arrived on time 90.0% of the time and Tuesday flights 87.6%, against 81.2% for the route overall.

The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

Key figures

On time

81.2%

Arrivals under 15 minutes late, of 1,352 completed flights

Avg delay

69 min

Across delayed arrivals only, not all flights

Cancelled

0.88%

National rate is 1.81%

Best carrier

United

82.2% on time across 1,180 flights

These figures cover 1,366 flights between July 2025 and June 2026. The median arrival is 8 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 IAD to TPA

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 IAD to TPA
AirlineFlightsOn timeAvg delayCancelledGrade
United Airlines1,18082.2%67 min0.42%B+
Frontier Airlinesthin sample18674.9%77 min3.76%C−

Flight by flight

Flights on IAD to TPA

The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.

Best ways to make this trip

The most reliable ways to fly Washington to Tampa

Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 4 of the top 5 use a different airport at one end.

Most reliable ways to fly from IAD to TPA
OptionAirlineSuccessOn timeCancelledBest departureMost punctual flight
1. IADTPAWashington to TampaUnited Airlines81.9%82.2%0.42%8am–11am, TueUA 683 09:00
2. BWISRQBaltimore to SarasotaSouthwest Airlines78.8%80.0%1.49%8am–11am, Wed
3. BWITPABaltimore to TampaSouthwest Airlines78.1%79.3%1.55%5am–8am, Wed
4. DCATPAWashington to TampaSouthwest Airlines77.2%78.7%1.85%5am–8am, Tue
5. DCATPAWashington to TampaAmerican Airlines70.3%72.2%2.70%5am–8am, Sat

Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.

Plan this trip by month, day and time

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 23 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–11am391 flights90.0%
  • 11am–2pm379 flights87.5%
  • 2pm–5pm70 flights78.5%
  • 5pm–8pm406 flights67.0%
  • 8pm–5am120 flights82.4%

Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 90.0% of the time, against 67.0% for the evening window. That is 23 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 406 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 32 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.

On-time rate by calendar month87J88F81M93A91M82J61J76A81S84O85N81D
Darker means more delays. Figures are on-time percentages.April best, July worst

July is the worst month at 61.4% on time, 32 points below April, the best at 92.9%. 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 170 flights.

Across the week, Tuesday is the strongest day at 87.6% on time and Sunday the weakest at 76.5%. 11 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week79.7Mon87.6Tue84.5Wed81.5Thu79.1Fri81.2Sat76.5Sun
Monday: 79.7 percent on time. Tuesday: 87.6 percent on time. Wednesday: 84.5 percent on time. Thursday: 81.5 percent on time. Friday: 79.1 percent on time. Saturday: 81.2 percent on time. Sunday: 76.5 percent on time

Delay causes

Why this route gets delayed

One category carries most of the weight here. Late-arriving aircraft accounts for 43% of the 17,000 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
    43%
  • National Airspace System
    30%
  • Carrier
    19%
  • Extreme weather
    8%

43% 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 17,000 reported delay minutes here, that single category outweighs weather by 5 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 17,418 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 90.0% on time here.

Cancellations are rare at 0.88%, 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

6.7% 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 a little over an hour, which a normal layover absorbs.

The 811 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

The return leg runs 83.7% on time across 1,368 flights, within 3 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

The sample behind these figures is 1,366 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.

Work out the risk of missing a connection in TPA after this flight

What to do with this

Booking this route

Put together: the calendar is the biggest lever here, not the carrier or the hour. April runs 92.9% on time and July 61.4%, a swing of 32 points. If the dates move at all, move them out of July before you think about anything else. 1,352 completed flights over 12 months sit behind that.

Common questions

IAD to TPA questions

How often is IAD to TPA delayed?

About one flight in five arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 18.8% of the 1,366 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.

How reliable is IAD to TPA compared with the rest of the country?

81.2% of flights arrive on time here against a national 77.6%, a difference of 4 points in its favour. That is worth a B+ on this site's grading scale.

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

The 8am–11am departure window is the strongest at 90.0% on time. The 5pm–8pm window is the weakest at 67.0%, 23 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 IAD to TPA?

July is the weakest month at 61.4% on time, compared with 92.9% in April. Across the year that is 32 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Related

Where to go next

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

Embed IAD to TPA’s on-time badge on your site

Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.

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.