ON TIMEBOARD

IAD → LGA on time

Washington Dulles (Washington, DC) to LaGuardia (New York, NY). Every scheduled flight, September 2025 to August 2026.

On time
68%
arrived < 15 min late
Cancelled
6.9%
1,450 flights
Typical arrival
−6 min
median vs schedule
When late
+75 min
average delay
Flights / day
4
1 airline

68% of flights from Washington to New York arrived on time over the past 12 months. That is worse than the typical U.S. route. The 8 a.m. departures ran on time 77% of the time; the noon ones 64%. 16% of flights arrived more than an hour late or not at all.

How late?

The on-time rate treats a flight 20 minutes late the same as one 5 hours late. Here's the split for IAD → LGA: when a flight was late, it was under 45 minutes late 48% of the time. About 1 in 11 flights landed an hour or more late, and 1 in 56 three hours or more; 6.9% were cancelled outright.

Share of all 1,450 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
United Airlines1,45068%6.9%−6 min9.3%+75 minRepublic Airways 63%, Mesa Airlines 37%

Airline = the name on the ticket. Regional flights (e.g. "Delta Connection") count under the ticketing airline, and the operator is listed.

Best time of day to fly

On-time rate by scheduled departure hour (local time at IAD). Delays build through the day as late planes knock on, so early flights usually do best.

40%70%100%8 a.m. departures: 77% on time (363 flights)778a9 a.m. departures: too few flights9a10 a.m. departures: too few flights10a11 a.m. departures: too few flights11anoon departures: 64% on time (362 flights)6412p1 p.m. departures: too few flights1p2 p.m. departures: too few flights2p3 p.m. departures: too few flights3p4 p.m. departures: too few flights4p5 p.m. departures: 64% on time (365 flights)645p6 p.m. departures: too few flights6p7 p.m. departures: too few flights7p8 p.m. departures: too few flights8p9 p.m. departures: too few flights9p10 p.m. departures: 68% on time (360 flights)6810p
IAD → LGA, share of flights arriving on time, by departure hour. Hours with under 100 flights are greyed out.
82%+ on time76–82%68–76%under 68%too few flights

Last flight of the day

On IAD → LGA, each airline's last flight of the day was cancelled 7.7% of the time, against 6.6% for its earlier flights, about the same. It arrived 3+ hours late 0.8% of the time (earlier flights: 2.2%). It matters more than the numbers suggest. Miss an earlier flight and there's another one that evening; miss the last one and you're usually waiting until morning.

AirlineLast departureLast: cancelledLast: 3h+ lateEarlier: cancelledNext morning
United Airlines10:05 p.m.7.7%0.8%6.6%first flight 8:19 a.m.

Last flight = the airline's last scheduled departure on this route that day, on days it flies the route at least twice; past 12 months. Times are typical scheduled times over the latest three months.

By month

Each calendar month pooled over 2023–2026. Best: October (81%). Worst: July (59%).

40%70%100%Jan: 77% on time (452 flights)77JanFeb: 77% on time (434 flights)77FebMar: 71% on time (431 flights)71MarApr: 75% on time (356 flights)75AprMay: 68% on time (374 flights)68MayJun: 63% on time (363 flights)63JunJul: 59% on time (370 flights)59JulAug: 66% on time (372 flights)66AugSep: 77% on time (410 flights)77SepOct: 81% on time (423 flights)81OctNov: 71% on time (409 flights)71NovDec: 73% on time (410 flights)73Dec

By day of week

DayFlightsOn timeCancelled
Monday21265%9.4%
Tuesday20871%5.8%
Wednesday20767%6.8%
Thursday20767%7.2%
Friday20864%4.8%
Saturday20079%5.5%
Sunday20863%8.6%

Why flights were late

Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.

Air traffic & airport (NAS) 57%Airline (crew, maintenance, ops) 19%Late inbound plane 15%Severe weather 9%

Cancellations: weather 51 · air traffic/airport 49

Month by month

40%70%100%Sep 2023Jan 2024Jan 2025Jan 2026Sep 2023: 69% on time, 10.0% cancelledOct 2023: 81% on time, 0.0% cancelledNov 2023: 83% on time, 0.0% cancelledDec 2023: 80% on time, 0.0% cancelledJan 2024: 78% on time, 5.9% cancelledFeb 2024: 83% on time, 1.9% cancelledMar 2024: 80% on time, 0.0% cancelledApr 2024: 82% on time, 0.8% cancelledMay 2024: 79% on time, 0.8% cancelledJun 2024: 68% on time, 5.0% cancelledJul 2024: 62% on time, 5.7% cancelledAug 2024: 59% on time, 11.3% cancelledSep 2024: 84% on time, 0.0% cancelledOct 2024: 83% on time, 0.0% cancelledNov 2024: 71% on time, 0.0% cancelledDec 2024: 73% on time, 0.0% cancelledJan 2025: 74% on time, 5.7% cancelledFeb 2025: 72% on time, 5.4% cancelledMar 2025: 73% on time, 1.6% cancelledApr 2025: 75% on time, 0.0% cancelledMay 2025: 55% on time, 7.1% cancelledJun 2025: 55% on time, 8.1% cancelledJul 2025: 52% on time, 14.6% cancelledAug 2025: 75% on time, 3.2% cancelledSep 2025: 79% on time, 3.3% cancelledOct 2025: 77% on time, 1.6% cancelledNov 2025: 55% on time, 15.1% cancelledDec 2025: 63% on time, 4.8% cancelledJan 2026: 80% on time, 7.3% cancelledFeb 2026: 72% on time, 6.5% cancelledMar 2026: 57% on time, 13.7% cancelledApr 2026: 69% on time, 1.7% cancelledMay 2026: 72% on time, 2.4% cancelledJun 2026: 66% on time, 6.7% cancelledJul 2026: 64% on time, 12.2% cancelledAug 2026: 64% on time, 7.3% cancelled
Share of flights on time, by month (hover a point for cancellations)
IAD → LGA, monthly on-time and cancellation rate.

Flight numbers on this route

Regular flights with at least 120 scheduled trips in the past year. Sorted by departure time.

FlightDepartsFlightsOn timeCancelledTypical arrivalOperated by
UA 369812:40 p.m.18665%4.8%0 minRepublic Airways
UA 341310:08 p.m.19574%4.1%−7 minRepublic Airways

Worst days in the past year

DateFlightsOn timeCancelled
Aug 27, 202640%2
Mar 12, 202640%1
Feb 23, 202640%4
Jul 18, 202640%2
Nov 20, 202540%0

Nearby airport alternatives

Other ways to make the same trip, using airports within 60 miles of Washington or New York. BWI → ISP has been 8 points more reliable.

RouteFlightsOn timeCancelled
IAD → LGA (this route)1,45068%6.9%
BWI → ISP Baltimore/Washington to Long Island MacArthur1,26076%1.9%
IAD → EWR Washington Dulles to Newark1,82474%2.9%
DCA → JFK Washington Reagan National to New York JFK2,72973%6.1%
DCA → EWR Washington Reagan National to Newark3,24767%6.4%
DCA → LGA Washington Reagan National to LaGuardia4,84461%6.4%
DCA → HPN Washington Reagan National to Westchester1,35457%7.3%

Questions

How often are flights from IAD to LGA on time?

68% of 1,450 scheduled flights from Washington, DC to New York, NY arrived within 15 minutes of schedule between September 2025 and August 2026. 6.9% were cancelled.

What is the best time of day to fly IAD to LGA?

Flights scheduled to leave at 8 a.m. were the most reliable (77% on time). The noon departures were the least (64%).

What month has the most delays from IAD to LGA?

July (59% on time). The best month is October (81%), over 2023–2026.

Is the last flight of the day from IAD to LGA more likely to be cancelled?

Not much. Each airline's last IAD–LGA flight of the day was cancelled 7.7% of the time over the past year, against 6.6% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.

Related

Domestic flights by the airlines that report to the U.S. DOT, plus their regional partners. "On time" means arriving less than 15 minutes after schedule; cancelled and diverted flights count as not on time. Past performance is a guide, not a forecast. Method.