ON TIMEBOARD

IAD → BTV on time

Washington Dulles (Washington, DC) to Patrick Leahy Burlington (Burlington, VT). Every scheduled flight, September 2025 to August 2026.

On time
76%
arrived < 15 min late
Cancelled
2.3%
1,223 flights
Typical arrival
−5 min
median vs schedule
When late
+91 min
average delay
Flights / day
3
1 airline

76% of flights from Washington to Burlington arrived on time over the past 12 months. That is about the typical U.S. route. The 8 a.m. departures ran on time 89% of the time; the 5 p.m. ones 68%. 10% 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 → BTV: when a flight was late, it was under 45 minutes late 53% of the time. About 1 in 13 flights landed an hour or more late, and 1 in 39 three hours or more; 2.3% were cancelled outright.

Share of all 1,223 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
United Airlines1,22376%2.3%−5 min7.5%+91 minGoJet 36%, Republic Airways 32%, CommutAir 19%, United Airlines 7%, Mesa Airlines 6%

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: 89% on time (331 flights)898a9 a.m. departures: too few flights (1 flights)9a10 a.m. departures: too few flights10a11 a.m. departures: too few flights11anoon departures: 75% on time (356 flights)7512p1 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: 68% on time (352 flights)685p6 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: 72% on time (183 flights)7210p
IAD → BTV, 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 → BTV, each airline's last flight of the day was cancelled 3.8% of the time, against 1.6% for its earlier flights (2.4× as often). It arrived 3+ hours late 2.7% of the time (earlier flights: 2.6%). 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 Airlines5:22 p.m.3.8%2.7%1.6%first flight 8:35 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.

If you need to be in BTV tonight, book an earlier flight so there's a backup if it's cancelled.

By month

Each calendar month pooled over 2023–2026. Best: October (89%). Worst: December (70%).

40%70%100%Jan: 71% on time (254 flights)71JanFeb: 80% on time (240 flights)80FebMar: 78% on time (296 flights)78MarApr: 81% on time (321 flights)81AprMay: 75% on time (333 flights)75MayJun: 79% on time (328 flights)79JunJul: 74% on time (335 flights)74JulAug: 79% on time (335 flights)79AugSep: 84% on time (288 flights)84SepOct: 89% on time (316 flights)89OctNov: 86% on time (251 flights)86NovDec: 70% on time (277 flights)70Dec

By day of week

DayFlightsOn timeCancelled
Monday17878%4.5%
Tuesday16877%1.2%
Wednesday17577%1.1%
Thursday18375%1.6%
Friday18576%1.6%
Saturday15274%2.6%
Sunday18276%3.3%

Why flights were late

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

Late inbound plane 53%Airline (crew, maintenance, ops) 27%Air traffic & airport (NAS) 15%Severe weather 5%

Cancellations: weather 21 · air traffic/airport 6 · airline 1

Month by month

50%75%100%Sep 2023Jan 2024Jan 2025Jan 2026Jun 2024: 84% on time, 0.0% cancelledJul 2024: 78% on time, 1.8% cancelledAug 2024: 76% on time, 4.3% cancelledSep 2024: 88% on time, 0.0% cancelledOct 2024: 93% on time, 0.0% cancelledNov 2024: 92% on time, 0.0% cancelledDec 2024: 76% on time, 0.9% cancelledMar 2025: 79% on time, 1.7% cancelledApr 2025: 80% on time, 0.7% cancelledMay 2025: 66% on time, 0.7% cancelledJun 2025: 71% on time, 2.3% cancelledJul 2025: 72% on time, 9.4% cancelledAug 2025: 84% on time, 0.9% cancelledOct 2025: 87% on time, 0.0% cancelledDec 2025: 57% on time, 0.0% cancelledMar 2026: 74% on time, 1.7% cancelledApr 2026: 81% on time, 0.0% cancelledMay 2026: 82% on time, 1.8% cancelledJul 2026: 71% on time, 8.3% cancelledAug 2026: 76% on time, 4.4% cancelled
Share of flights on time, by month (hover a point for cancellations)
IAD → BTV, monthly on-time and cancellation rate.

Worst days in the past year

DateFlightsOn timeCancelled
Dec 27, 202540%0
Jul 18, 202630%3
Dec 5, 202530%0
Jan 26, 202630%3
Nov 11, 202530%0

Nearby airport alternatives

Other ways to make the same trip, using airports within 60 miles of Washington or Burlington. None has been clearly more reliable than IAD → BTV.

RouteFlightsOn timeCancelled
IAD → BTV (this route)1,22376%2.3%
DCA → BTV Washington Reagan National to Patrick Leahy Burlington1,11963%5.5%

Questions

How often are flights from IAD to BTV on time?

76% of 1,223 scheduled flights from Washington, DC to Burlington, VT arrived within 15 minutes of schedule between September 2025 and August 2026. 2.3% were cancelled.

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

Flights scheduled to leave at 8 a.m. were the most reliable (89% on time). The 5 p.m. departures were the least (68%).

What month has the most delays from IAD to BTV?

December (70% on time). The best month is October (89%), over 2023–2026.

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

Yes. Each airline's last IAD–BTV flight of the day was cancelled 3.8% of the time over the past year, against 1.6% 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.