Route profile
IAD→JAX
Flight reliability, delays and best times to fly from Washington to Jacksonville, 630 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 46% of comparable major US routes (4,598 compared)
Calculated from 2,458 flights. How this is calculated
IAD → JAX arrives on time 78.6% of the time; the return trip, JAX → IAD, arrives on time 84.5% of the time, a 5.8-point gap between the two directions of the same city pair.
IAD → JAX spends 29.3 minutes on the ground on a 630-mile trip: 21.9 minutes from pushback to wheels-up at IAD and 7.3 minutes from touchdown to gate at JAX.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
The airline matters unusually much on this route, a wider carrier-to-carrier gap than 98% of 2,692 comparable routes.
United Airlines arrived on time 80.8% of the time, against 56.7% for Allegiant Air, flying the exact same route.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 2,692 in the comparison.
What sets this route apart
Where IAD to JAX differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
IAD to JAX is at its best against routes of similar length for flights scheduled at 12 PM: 85.4% arrive on time, 4.8 points ahead of the 80.6% those routes manage at that hour. Against all other routes the gap is 6 points.
February is kinder to IAD to JAX than to routes of similar length: 88.4% on time against 81.7%, 6.7 points better. Against all other routes the gap is 7 points.
United Airlines does better on IAD to JAX than on its routes of similar length: 80.8% on time here, 78.1% there, 2.7 points apart.
IAD to JAX against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 12 PM departures | 85.4% | routes of similar length | 80.6% | +4.8 pts | 268 here, 106,983 there |
| Month: February | 88.4% | routes of similar length | 81.7% | +6.7 pts | 155 here, 144,186 there |
| Airline: United Airlines | 80.8% | routes of similar length | 78.1% | +2.7 pts | 1,911 here, 217,773 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 630 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
When it goes wrong
July 2023 – July 2026
46 min late
against a median of 7 min early
Percentiles over 2,458 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at JAX after arriving from IAD.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 34% | Likely to miss |
| 45 min | 21% | High risk |
| 60 min | 14% | Some risk |
| 90 min | 7.6% | Some risk |
| 120 min | 5.6% | Some risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 1.06% of the time and diverts 0.12% of the time, which a late arrival never shows up in.
Chance of missing is the share of 2,429 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 46 minutes late (90th-percentile gate arrival delay), over 2,458 operations.
Any other layover length: connection checker.
Best time to fly
IAD → JAX flights departing 5–9 AM arrived on time 85.6% of the time, against 61.2% for 6–9 PM departures, a gap of 24.4 percentage points.
By departure window
By departure hour
- 12 AM to 7 AM: too few flights to score
- 8 AM: 85.6% on time from 831 flights
- 9 AM to 11 AM: too few flights to score
- 12 PM: 85.4% on time from 270 flights
- 1 PM to 4 PM: too few flights to score
- 5 PM: 73.0% on time from 871 flights
- 6 PM: 61.8% on time from 205 flights
- 7 PM to 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why IAD → JAX runs late
July 2023 – July 2026
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for IAD → JAX. Only delays of 15 minutes or more are attributed.
Late-arriving aircraft is the largest cause on IAD → JAX, at 35.6%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 85.6% of the time and 6–9 PM departures 61.2%.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| United Airlines | 1,928 | 80.8% | 0.78% | -7 min | 6.9% |
| Republic Airways | 311 | 80.5% | 2.25% | -12 min | 4.3% |
| Allegiant Air | 219 | 56.7% | 1.83% | 9 min | 20.5% |
United Airlines flew 78.4% of the 2,458 flights listed. Republic Airways cancelled 2.25% of its flights here against 0.78% for United Airlines.
United Airlines arrived on time 24.1 percentage points more often than Allegiant Air on this route.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
| Flight | Scheduled | Operations | On time |
|---|---|---|---|
| UA2084 United Airlines | 8:45 AM | 702 | 85.5% |
Weekly and seasonal patterns
By day of week
Wednesday is historically the most reliable day and Friday the least, a gap of 10.7 percentage points.
By month
- Jan: 79.4%
- Feb: 88.4%
- Mar: 78.2%
- Apr: 85.7%
- May: 74.8%
- Jun: 74.6%
- Jul: 66.9%
- Aug: 76.6%
- Sep: 85.6%
- Oct: 85.4%
- Nov: 78.7%
- Dec: 78.0%
July is historically the weakest month and February the strongest, a spread of 21.5 percentage points.
Reliability over time
July 2023 – July 2026
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 83.5% against 72.2% in the 12 months before — improving by 11.3 percentage points.
Data and methodology
Calculated by FlyerIntel from 2,458 IAD → JAX flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed