ON TIMEBOARD

IAD → GSO on time

Washington Dulles (Washington, DC) to Piedmont Triad (Greensboro/High Point, NC). Every scheduled flight, September 2025 to August 2026.

On time
80%
arrived < 15 min late
Cancelled
2.2%
739 flights
Typical arrival
−8 min
median vs schedule
When late
+97 min
average delay
Flights / day
2
1 airline

80% of flights from Washington to Greensboro arrived on time over the past 12 months. That is about the typical U.S. route. The noon departures ran on time 82% of the time; the 10 p.m. ones 76%. 9% 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 → GSO: when a flight was late, it was under 45 minutes late 44% of the time. About 1 in 15 flights landed an hour or more late, and 1 in 49 three hours or more; 2.2% were cancelled outright.

Share of all 739 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
United Airlines73980%2.2%−8 min6.6%+97 minCommutAir 86%, GoJet 14%

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: too few flights (81 flights)8a9 a.m. departures: too few flights9a10 a.m. departures: too few flights10a11 a.m. departures: too few flights11anoon departures: 82% on time (280 flights)8212p1 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: 77% on time (217 flights)775p6 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: 76% on time (161 flights)7610p
IAD → GSO, 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 → GSO, each airline's last flight of the day was cancelled 3.4% of the time, against 1.1% for its earlier flights (3.1× as often). It arrived 3+ hours late 2.4% of the time (earlier flights: 1.6%). 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 Airlines10:15 p.m.3.4%2.4%1.1%first flight 12:58 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 GSO tonight, book an earlier flight so there's a backup if it's cancelled.

By month

Each calendar month pooled over 2023–2026. Best: November (87%). Worst: December (61%).

40%70%100%Jan: 66% on time (122 flights)66JanFeb: 76% on time (104 flights)76FebMar: 80% on time (123 flights)80MarApr: 85% on time (159 flights)85AprMay: 79% on time (185 flights)79MayJun: 69% on time (161 flights)69JunJul: 68% on time (136 flights)68JulAug: 79% on time (138 flights)79AugSep: too few flights (70 flights)SepOct: too few flights (77 flights)OctNov: 87% on time (143 flights)87NovDec: 61% on time (132 flights)61Dec

By day of week

DayFlightsOn timeCancelled
Monday11878%4.2%
Tuesday10786%0.9%
Wednesday10783%2.8%
Thursday11381%0.0%
Friday11379%1.8%
Saturday69——
Sunday11275%3.6%

Why flights were late

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

Late inbound plane 44%Airline (crew, maintenance, ops) 37%Air traffic & airport (NAS) 18%Severe weather 2%

Cancellations: weather 13 · air traffic/airport 3

Month by month

60%80%100%Oct 2024Jan 2025Jan 2026May 2025: 74% on time, 2.8% cancelledJun 2025: 67% on time, 2.9% cancelled
Share of flights on time, by month (hover a point for cancellations)
IAD → GSO, 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 434912:58 p.m.18579%2.7%−6 minCommutAir
UA 484910:15 p.m.12273%4.1%−8 minCommutAir

Worst days in the past year

DateFlightsOn timeCancelled
May 4, 2026333%1
Sep 19, 2025367%0
Apr 5, 2026367%0
May 13, 2026367%0
May 3, 2026367%0

Nearby airport alternatives

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

RouteFlightsOn timeCancelled
IAD → GSO (this route)73980%2.2%
DCA → GSO Washington Reagan National to Piedmont Triad76772%4.7%

Questions

How often are flights from IAD to GSO on time?

80% of 739 scheduled flights from Washington, DC to Greensboro/High Point, NC arrived within 15 minutes of schedule between September 2025 and August 2026. 2.2% were cancelled.

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

Flights scheduled to leave at noon were the most reliable (82% on time). The 10 p.m. departures were the least (76%).

What month has the most delays from IAD to GSO?

December (61% on time). The best month is November (87%), over 2023–2026.

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

Yes. Each airline's last IAD–GSO flight of the day was cancelled 3.4% of the time over the past year, against 1.1% 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.