Route reliability record
EWR→IAD
Newark to Washington
- Flights
- 1,502
- Period
- July 2025 to June 2026
- Distance
- 212 mi
- Carriers
- 2
This route sits in the middle of the pack with a C. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 1,502 EWR to IAD flights, with a median arrival 5 minutes early.
Best time to fly EWR to IAD: a 5am–8am departure, ideally on a Saturday. Flights in that window arrived on time 96.3% of the time and Saturday flights 80.4%, against 73.9% 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
73.9%
Arrivals under 15 minutes late, of 1,466 completed flights
Avg delay
75 min
Across delayed arrivals only, not all flights
Cancelled
2.33%
National rate is 1.81%
Best carrier
United
73.9% on time across 1,474 flights
These figures cover 1,502 flights between July 2025 and June 2026. Beyond the headline rate, 10.4% 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 EWR 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 |
|---|---|---|---|---|---|
| United Airlines | 1,474 | 73.9% | 75 min | 2.24% | C |
| Republic Airwaysthin sample | 28 | 73.1% | 68 min | 7.14% | C− |
Flight by flight
Flights on EWR 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 Newark 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. 4 of the top 5 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. ISP → BWIIslip to Baltimore | Southwest Airlines | 83.6% | 84.9% | 1.48% | 5am–8am, Fri | — |
| 2. EWR → IADNewark to Washington | United Airlines | 72.2% | 73.9% | 2.24% | 5am–8am, Sat (route) | UA 1366 06:00 |
| 3. LGA → IADNew York to Washington | Republic Airways | 70.3% | 75.4% | 6.73% | 5am–8am, Sat | YX 3688 14:59 |
| 4. JFK → DCANew York to Washington | Republic Airways | 66.9% | 70.7% | 5.38% | 5am–8am, Sat | YX 4538 06:30 |
| 5. LGA → DCANew York to Washington | Republic Airways | 64.6% | 68.4% | 5.51% | 5am–8am, Sat (route) | YX 5770 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.
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 34 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–8am364 flights96.3%
- 8am–11am43 flights88.4%
- 11am–2pm—
- 2pm–5pm365 flights65.5%
- 5pm–8pm266 flights62.3%
- 8pm–5am464 flights68.0%
Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 62.3% on time, against 96.3% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 8pm–5am window is the busiest, with 464 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 39 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 47.8% on time, 39 points below May, the best at 86.5%. 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 150 flights.
Across the week, Saturday is the strongest day at 80.4% on time and Sunday the weakest at 62.6%. 18 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 45% of the 29,000 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.
- 45%Late-arriving aircraft
- 27%Carrier
- 25%National Airspace System
- 4%Extreme weather
45% 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 29,000 reported delay minutes here, that single category outweighs weather by 12 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 28,578 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 96.3% on time here.
Cancellations sit at 2.33% against a national 1.81%, which is ordinary. Diversions add another 0.07%.
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. 10.4% 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.
At 212 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.
The return leg runs 75.3% on time across 1,501 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 1,502 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 IAD 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. May runs 86.5% on time and July 47.8%, a swing of 39 points. If the dates move at all, move them out of July before you think about anything else. 1,466 completed flights over 12 months sit behind that.
Common questions
EWR to IAD questions
How often is EWR to IAD delayed?
About 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 26.1% of the 1,502 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
How reliable is EWR to IAD compared with the rest of the country?
73.9% of flights arrive on time here against a national 77.6%, a difference of 4 points against it. That is worth a C on this site's grading scale.
What time of day has the fewest delays on EWR to IAD?
The 5am–8am departure window is the strongest at 96.3% on time. The 5pm–8pm window is the weakest at 62.3%, 34 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 EWR to IAD?
July is the weakest month at 47.8% on time, compared with 86.5% in May. Across the year that is 39 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 EWR — the return legseparate record
- Newark Liberty International (EWR) delay statistics
- Washington Dulles International (IAD) delay statistics
- EWR to MCO, a related route77.1%
- ATL to IAD, a related route76.5%
- EWR to ATL, a related route77.6%
- United Airlines on-time record73.9%
- Republic Airways on-time record73.1%
- Why the first flight of the morning is statistically safest
- How often a connection fails at the major US hubs
Direction matters. EWR to IAD and IAD to EWR 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.