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DelayAtlas

Route reliability record

TPAIAH

Tampa to Houston

Flights
1,650
Period
July 2025 to June 2026
Distance
787 mi
Carriers
3
B+GRADE

This route earns a B+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.6%. When something does go wrong the average delay runs an hour and a half. That rests on 1,650 TPA to IAH flights, with a median arrival 14 minutes early.

Best time to fly TPA to IAH: a 5am–8am departure, ideally on a Saturday. Flights in that window arrived on time 92.7% of the time and Saturday flights 88.2%, against 84.7% for the route overall.

Set against the rest of the country, this route's record is 7 points better than the US average of 77.6%. That gap is worth roughly 71 fewer late arrivals for every thousand flights.

Key figures

On time

84.7%

Arrivals under 15 minutes late, of 1,640 completed flights

Avg delay

83 min

Across delayed arrivals only, not all flights

Cancelled

0.48%

National rate is 1.81%

Best carrier

United

87.3% on time across 1,362 flights

These figures cover 1,650 flights between July 2025 and June 2026. The median arrival is 14 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 TPA to IAH

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 TPA to IAH
AirlineFlightsOn timeAvg delayCancelledGrade
United Airlines1,36287.3%76 min0.29%A+
Spirit Airlinesthin sample15173.2%99 min1.32%C
Frontier Airlinesthin sample13771.1%101 min1.46%C

Best ways to make this trip

The most reliable ways to fly Tampa to Houston

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. 1 of the top 2 use a different airport at one end.

Most reliable ways to fly from TPA to IAH
OptionAirlineSuccessOn timeCancelledBest departureMost punctual flight
1. TPAIAHTampa to HoustonUnited Airlines87.0%87.3%0.29%5am–8am, Sat
2. TPAHOUTampa to HoustonSouthwest Airlines81.1%81.4%0.39%5am–8am, Tue

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 20 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–8am384 flights92.7%
  • 8am–11am350 flights85.6%
  • 11am–2pm401 flights89.4%
  • 2pm–5pm91 flights81.3%
  • 5pm–8pm418 flights73.0%
  • 8pm–5am6 flights

Scale runs 65% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 92.7% of the time, against 73.0% for the evening window. That is 20 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 418 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 19 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 month89J96F87M84A81M77J78J77A95S82O88N84D
Darker means more delays. Figures are on-time percentages.February best, June worst

June is the worst month at 77.1% on time, 19 points below February, the best at 95.7%. 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 177 flights.

Across the week, Saturday is the strongest day at 88.2% on time and Sunday the weakest at 79.5%. 9 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week85.1Mon87.7Tue87.7Wed85.0Thu81.1Fri88.2Sat79.5Sun
Monday: 85.1 percent on time. Tuesday: 87.7 percent on time. Wednesday: 87.7 percent on time. Thursday: 85.0 percent on time. Friday: 81.1 percent on time. Saturday: 88.2 percent on time. Sunday: 79.5 percent on time

Delay causes

Why this route gets delayed

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 21,000 reported delay minutes.

  • National Airspace System
    35%
  • Carrier
    29%
  • Late-arriving aircraft
    29%
  • Extreme weather
    6%

35% 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 7,418 minutes out of 21,000, against a national NAS share of 21%. The split is drawn from 20,943 reported delay minutes.

The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 92.7% on time here.

Cancellations are rare at 0.48%, 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

6.0% 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 an hour and a half, which a normal layover absorbs.

The 787 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 is a different operation and performs like one: it runs 81.6% on time across 1,643 flights, 3 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 3 points of difference.

The sample behind these figures is 1,650 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 IAH 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. February runs 95.7% on time and June 77.1%, a swing of 19 points. If the dates move at all, move them out of June before you think about anything else. 1,640 completed flights over 12 months sit behind that.

Common questions

TPA to IAH questions

How often is TPA to IAH delayed?

About one flight in seven arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 15.3% of the 1,650 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.

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

84.7% of flights arrive on time here against a national 77.6%, a difference of 7 points in its favour. That is worth a B+ on this site's grading scale.

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

The 5am–8am departure window is the strongest at 92.7% on time. The 5pm–8pm window is the weakest at 73.0%, 20 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 June delays on TPA to IAH?

June is the weakest month at 77.1% on time, compared with 95.7% in February. Across the year that is 19 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. TPA to IAH and IAH to TPA are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Embed TPA to IAH’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.