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DelayAtlas

Route reliability record

IADDFW

Washington to Dallas-Fort Worth

Flights
1,928
Period
July 2025 to June 2026
Distance
1,172 mi
Carriers
4
BGRADE

This route lands a B, level with the national rate of 77.6%. Roughly one flight in four arrives 15 minutes late or worse, and those flights are late by close to two hours on average. That is a workable record, not a spotless one. That rests on 1,928 IAD to DFW flights, of which United Airlines flew 914 at 79.8% on time.

Best time to fly IAD to DFW: a 8am–11am departure, ideally on a Tuesday. Flights in that window arrived on time 87.5% of the time and Tuesday flights 80.4%, against 77.1% 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

77.1%

Arrivals under 15 minutes late, of 1,868 completed flights

Avg delay

104 min

Across delayed arrivals only, not all flights

Cancelled

2.23%

National rate is 1.81%

Best carrier

United

79.8% on time across 914 flights

These figures cover 1,928 flights between July 2025 and June 2026. Beyond the headline rate, 9.5% 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

Which airline is most reliable on IAD to DFW

The choice of carrier is not cosmetic here. United Airlines arrives on time 79.8% of the time; American Airlines manages 73.3%. Sample sizes sit next to every figure, because a two-point gap across 844 flights means less than a ten-point one.

On-time performance by carrier on IAD to DFW
AirlineFlightsOn timeAvg delayCancelledGrade
Frontier Airlinesthin sample16181.3%213 min3.11%B−
United Airlines91479.8%82 min0.77%B+
American Airlines84473.3%108 min3.67%C−
Republic Airwaysthin sample966.7%69 min0.00%C+

American Airlines cancels 3.7% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.

Flight by flight

Flights on IAD to DFW

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 Dallas-Fort Worth

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. 3 of the top 5 use a different airport at one end.

Most reliable ways to fly from IAD to DFW
OptionAirlineSuccessOn timeCancelledBest departureMost punctual flight
1. IADDFWWashington to Dallas-Fort WorthUnited Airlines79.2%79.8%0.77%8am–11am, TueUA 2116 17:50
2. DCADFWWashington to Dallas-Fort WorthAmerican Airlines75.0%77.6%3.39%5am–8am, TueAA 1978 07:45
3. BWIDALBaltimore to DallasSouthwest Airlines74.8%76.2%1.87%5am–8am, Tue
4. DCADALWashington to DallasSouthwest Airlines71.8%73.1%1.84%5am–8am, Tue
5. IADDFWWashington to Dallas-Fort WorthAmerican Airlines70.6%73.3%3.67%5am–8am, WedAA 2617 06:00

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

  • 5am–8am364 flights82.4%
  • 8am–11am272 flights87.5%
  • 11am–2pm545 flights84.1%
  • 2pm–5pm22 flights
  • 5pm–8pm709 flights65.0%
  • 8pm–5am16 flights

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

Book the morning departure. Flights leaving between 8am–11am arrive on time 87.5% of the time, against 65.0% 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 709 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 21 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 month86J86F80M76A75M67J66J79A84S84O78N70D
Darker means more delays. Figures are on-time percentages.January best, July worst

July is the worst month at 65.7% on time, 21 points below January, the best at 86.2%. 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. June was the busiest month here, with 196 flights.

Across the week, Tuesday is the strongest day at 80.4% on time and Saturday the weakest at 71.5%. 9 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week77.3Mon80.4Tue77.4Wed79.3Thu78.6Fri71.5Sat74.5Sun
Monday: 77.3 percent on time. Tuesday: 80.4 percent on time. Wednesday: 77.4 percent on time. Thursday: 79.3 percent on time. Friday: 78.6 percent on time. Saturday: 71.5 percent on time. Sunday: 74.5 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 44,000 reported delay minutes.

  • Carrier
    39%
  • Late-arriving aircraft
    38%
  • National Airspace System
    17%
  • Extreme weather
    6%
  • Security
    0%

38% 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 44,000 reported delay minutes here, that single category outweighs weather by 6 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 44,358 reported delay minutes.

The largest share of delay minutes, 39%, 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 17,000 of the 44,000 delay minutes reported here.

Cancellations sit at 2.23% against a national 1.81%, which is ordinary. Diversions add another 0.88%.

Connections and stage length

What a delay here actually costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.5% 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.

The 1,172 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 78.2% on time across 1,928 flights, within about a point 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 1,928 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 DFW 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. January runs 86.2% on time and July 65.7%, a swing of 21 points. If the dates move at all, move them out of July before you think about anything else. 1,868 completed flights over 12 months sit behind that.

Common questions

IAD to DFW questions

How often is IAD to DFW delayed?

Roughly one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 22.9% of the 1,928 flights in this analysis, against 22.4% nationally. Delayed flights are late by close to two hours on average.

Which airline is most reliable on IAD to DFW?

United Airlines leads at 79.8% on time across 914 flights. American Airlines is at the other end on 73.3%, a gap of 7 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 IAD to DFW?

The 8am–11am departure window is the strongest at 87.5% on time. The 5pm–8pm window is the weakest at 65.0%, 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 DFW?

July is the weakest month at 65.7% on time, compared with 86.2% in January. Across the year that is 21 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 DFW and DFW to IAD are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

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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.