Route reliability record
JAX→IAD
Jacksonville to Washington
- Flights
- 771
- Period
- July 2025 to June 2026
- Distance
- 631 mi
- Carriers
- 3
This route earns an A. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 10 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 771 JAX to IAD flights, with a median arrival 13 minutes early.
Best time to fly JAX to IAD: a 8am–11am departure, ideally on a Saturday. Flights in that window arrived on time 93.1% of the time and Saturday flights 94.4%, against 88.0% for the route overall.
Set against the rest of the country, this route's record is 10 points better than the US average of 77.6%. That gap is worth roughly 104 fewer late arrivals for every thousand flights.
Key figures
On time
88.0%
Arrivals under 15 minutes late, of 761 completed flights
Avg delay
85 min
Across delayed arrivals only, not all flights
Cancelled
1.17%
National rate is 1.81%
Best carrier
United
90.6% on time across 591 flights
These figures cover 771 flights between July 2025 and June 2026. The median arrival is 13 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 JAX to IAD
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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Republic Airwaysthin sample | 120 | 94.0% | 103 min | 2.50% | A |
| United Airlines | 591 | 90.6% | 99 min | 1.02% | A |
| Allegiant Airthin sample | 60 | 51.7% | 53 min | 0.00% | F+ |
Flight by flight
Flights on JAX to IAD
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 Jacksonville to Washington
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. 2 of the top 3 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. JAX → IADJacksonville to Washington | United Airlines | 89.7% | 90.6% | 1.02% | 11am–2pm, Sat | UA 1938 13:25 |
| 2. JAX → BWIJacksonville to Baltimore | Southwest Airlines | 79.0% | 80.0% | 1.29% | 5am–8am, Thu | — |
| 3. JAX → DCAJacksonville to Washington | American Airlines | 70.0% | 71.6% | 2.19% | 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.
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 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–11am342 flights93.1%
- 11am–2pm273 flights91.9%
- 2pm–5pm113 flights65.8%
- 5pm–8pm43 flights81.4%
- 8pm–5am—
Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 93.1% of the time, against 65.8% for the afternoon window. That is 27 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 342 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 28 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.
July is the worst month at 70.5% on time, 28 points below September, the best at 98.2%. 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. March was the busiest month here, with 94 flights.
Across the week, Saturday is the strongest day at 94.4% on time and Friday the weakest at 80.3%. 14 points is a smaller lever than departure hour, but it is free.
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 7,708 reported delay minutes.
- 40%Carrier
- 33%National Airspace System
- 24%Late-arriving aircraft
- 3%Extreme weather
33% 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 2,519 minutes out of 7,708, against a national NAS share of 21%. The split is drawn from 7,708 reported delay minutes.
The largest share of delay minutes, 40%, 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 3,087 of the 7,708 delay minutes reported here.
Cancellations sit at 1.17% against a national 1.81%, which is ordinary. Diversions add another 0.13%.
Connections and stage length
What a delay here actually costs
Badly late arrivals are rare here: only 4.9% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The 631 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 83.1% on time across 772 flights, 5 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 5 points of difference.
One caution: this is a thin sample. 771 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
Work out the risk of missing a connection in IAD after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 771 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 88.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 761 completed flights over 12 months sit behind that.
Common questions
JAX to IAD questions
How often is JAX to IAD delayed?
About one flight in eight arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 12.0% of the 771 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.
How reliable is JAX to IAD compared with the rest of the country?
88.0% of flights arrive on time here against a national 77.6%, a difference of 10 points in its favour. That is worth a A on this site's grading scale.
What time of day has the fewest delays on JAX to IAD?
The 8am–11am departure window is the strongest at 93.1% on time. The 2pm–5pm window is the weakest at 65.8%, 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 JAX to IAD?
July is the weakest month at 70.5% on time, compared with 98.2% in September. Across the year that is 28 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
- IAD to JAX — the return legseparate record
- Washington Dulles International (IAD) delay statistics
- Republic Airways on JAX to IAD94.0%
- United Airlines on JAX to IAD90.6%
- JAX to ATL, a related route84.9%
- ATL to IAD, a related route76.5%
- JAX to ORD, a related route77.3%
- Republic Airways on-time record94.0%
- United Airlines on-time record90.6%
- Allegiant Air on-time record51.7%
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
Direction matters. JAX to IAD and IAD to JAX 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.