Route reliability record
LGA→IAD
New York to Washington
- Flights
- 980
- Period
- July 2025 to June 2026
- Distance
- 228 mi
- Carriers
- 1
This route carries a cancellation problem, not just a delay problem: 6.7% of scheduled flights never operate, against 1.8% nationally. Of the ones that do fly, close to three flights in four arrive on time, worth a B− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 980 LGA to IAD flights, with a median arrival 8 minutes early.
Best time to fly LGA to IAD: a 5am–8am departure, ideally on a Saturday. Flights in that window arrived on time 93.0% of the time and Saturday flights 83.7%, against 75.4% 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
75.4%
Arrivals under 15 minutes late, of 914 completed flights
Avg delay
85 min
Across delayed arrivals only, not all flights
Cancelled
6.73%
National rate is 1.81%
Best carrier
Republic
75.4% on time across 980 flights
These figures cover 980 flights between July 2025 and June 2026. Beyond the headline rate, 11.2% 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 LGA 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 Airways | 980 | 75.4% | 85 min | 6.73% | B− |
Flight by flight
Flights on LGA 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 New York 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–8am288 flights93.0%
- 8am–11am122 flights81.0%
- 11am–2pm—
- 2pm–5pm334 flights58.9%
- 5pm–8pm236 flights74.5%
- 8pm–5am—
Scale runs 50% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 93.0% of the time, against 58.9% for the afternoon window. That is 34 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 334 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 38 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 45.7% on time, 38 points below February, the best at 83.6%. 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. September was the busiest month here, with 111 flights.
Across the week, Saturday is the strongest day at 83.7% on time and Thursday the weakest at 72.2%. 12 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 50% of the 19,000 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.
- 50%Late-arriving aircraft
- 28%National Airspace System
- 18%Carrier
- 5%Extreme weather
50% 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 19,000 reported delay minutes here, that single category outweighs weather by 10 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 19,034 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 93.0% on time here.
Cancellations run at 6.73%, against 1.81% nationally. That is about one flight in fifteen cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
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. 11.2% 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 228 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 73.8% on time across 980 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 980 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: the delay figures matter less here than the 6.73% cancellation rate. A late arrival costs you an hour and a half; a cancelled flight costs you the day. Book the 5am–8am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 914 completed flights over 12 months sit behind that.
Common questions
LGA to IAD questions
How often is LGA 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 24.6% of the 980 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.
How reliable is LGA to IAD compared with the rest of the country?
75.4% of flights arrive on time here against a national 77.6%, a difference of 2 points against it. That is worth a B− on this site's grading scale.
What time of day has the fewest delays on LGA to IAD?
The 5am–8am departure window is the strongest at 93.0% on time. The 2pm–5pm window is the weakest at 58.9%, 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 LGA to IAD?
July is the weakest month at 45.7% on time, compared with 83.6% in February. Across the year that is 38 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 LGA — the return legseparate record
- LaGuardia (LGA) delay statistics
- Washington Dulles International (IAD) delay statistics
- LGA to ORD, a related route67.3%
- ATL to IAD, a related route76.5%
- LGA to ATL, a related route76.6%
- Republic Airways on-time record75.4%
- The US routes with the most cancellations
- Why the first flight of the morning is statistically safest
Direction matters. LGA to IAD and IAD to LGA 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.