ON TIMEBOARD

IAD → MHT on time

Washington Dulles (Washington, DC) to Manchester-Boston (Manchester, NH). Every scheduled flight, September 2025 to August 2026.

On time
76%
arrived < 15 min late
Cancelled
3.0%
731 flights
Typical arrival
−8 min
median vs schedule
When late
+100 min
average delay
Flights / day
2
1 airline

76% of flights from Washington to Manchester arrived on time over the past 12 months. That is worse than the typical U.S. route. The noon departures ran on time 81% of the time; the 5 p.m. ones 69%. 13% 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 → MHT: when a flight was late, it was under 45 minutes late 40% of the time. About 1 in 10 flights landed an hour or more late, and 1 in 41 three hours or more; 3.0% were cancelled outright.

Share of all 731 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
United Airlines73176%3.0%−8 min10.0%+100 minCommutAir

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%9 a.m. departures: too few flights (24 flights)9a10 a.m. departures: too few flights10a11 a.m. departures: too few flights11anoon departures: 81% on time (300 flights)8112p1 p.m. departures: too few flights (55 flights)1p2 p.m. departures: too few flights2p3 p.m. departures: too few flights3p4 p.m. departures: too few flights4p5 p.m. departures: 69% on time (260 flights)695p6 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: too few flights (92 flights)10p
IAD → MHT, 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 → MHT, each airline's last flight of the day was cancelled 4.2% of the time, against 2.2% for its earlier flights (1.9× as often). It arrived 3+ hours late 2.6% of the time (earlier flights: 2.5%). 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 Airlines10:10 p.m.4.2%2.6%2.2%first flight 12:16 p.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 MHT tonight, book an earlier flight so there's a backup if it's cancelled.

By month

Each calendar month pooled over 2023–2026. Best: April (78%). Worst: July (63%).

40%70%100%Jan: too few flights (58 flights)JanFeb: too few flights (51 flights)FebMar: too few flights (62 flights)MarApr: 78% on time (120 flights)78AprMay: 70% on time (156 flights)70MayJun: 65% on time (161 flights)65JunJul: 63% on time (152 flights)63JulAug: 75% on time (150 flights)75AugSep: too few flights (54 flights)SepOct: too few flights (37 flights)OctNov: too few flights (54 flights)NovDec: too few flights (59 flights)Dec

By day of week

DayFlightsOn timeCancelled
Monday10376%4.9%
Tuesday10078%4.0%
Wednesday10084%1.0%
Thursday11379%0.9%
Friday11372%2.6%
Saturday88——
Sunday11472%4.4%

Why flights were late

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

Late inbound plane 42%Airline (crew, maintenance, ops) 38%Severe weather 10%Air traffic & airport (NAS) 10%

Cancellations: weather 16 · air traffic/airport 4 · airline 2

Month by month

Not enough months with data to draw a trend.

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 493012:16 p.m.35579%2.0%−10 minCommutAir
UA 49325:15 p.m.22573%3.6%−6 minCommutAir

Worst days in the past year

DateFlightsOn timeCancelled
Aug 20, 202630%0
Jul 11, 202630%0
Jul 18, 202630%2
Jul 5, 202630%1
Jul 9, 2026333%1

Nearby airport alternatives

Other ways to make the same trip, using airports within 60 miles of Washington or Manchester. BWI → MHT has been 7 points more reliable.

RouteFlightsOn timeCancelled
IAD → MHT (this route)73176%3.0%
BWI → MHT Baltimore/Washington to Manchester-Boston1,72183%1.4%
IAD → BOS Washington Dulles to Boston Logan1,52475%2.8%
BWI → BOS Baltimore/Washington to Boston Logan3,54072%3.2%
DCA → BOS Washington Reagan National to Boston Logan9,10467%4.3%
DCA → MHT Washington Reagan National to Manchester-Boston1,05761%7.1%

Questions

How often are flights from IAD to MHT on time?

76% of 731 scheduled flights from Washington, DC to Manchester, NH arrived within 15 minutes of schedule between September 2025 and August 2026. 3.0% were cancelled.

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

Flights scheduled to leave at noon were the most reliable (81% on time). The 5 p.m. departures were the least (69%).

What month has the most delays from IAD to MHT?

July (63% on time). The best month is April (78%), over 2023–2026.

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

Yes. Each airline's last IAD–MHT flight of the day was cancelled 4.2% of the time over the past year, against 2.2% 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.