Best time to fly out of Portland Jetport (PWM)

The early-flight folk wisdom holds up at Portland Jetport: departures in the 8–10am band left on time 91.6% of the time, against 72.5% in the 6–8pm band. These are historical odds, not forecasts. The records say what happened on this schedule over three years; they know nothing about tomorrow’s thunderstorm.

Data through June 2026 · Bureau of Transportation Statistics

On-time rate by hour and day

On this page, “on time” means a departure that pushed back less than 15 minutes behind its scheduled time — the Bureau of Transportation Statistics definition, and the one airlines are held to.

Share of departures that left on time, by hour band and day of week.
Departure time MonTueWedThuFriSatSun
Before 6am 90 91 93 92 90 91 92
6–8am 89 92 94 92 91 91 90
8–10am 93 92 94 91 93 89 90
10am–12pm 83 88 90 88 84 85 84
12–2pm 78 83 85 79 76 78 77
2–4pm 75 78 80 77 75 76 69
4–6pm 72 78 78 76 71 72 70
6–8pm 68 79 78 73 75 65 70
8–10pm – – – – – – –
10pm–12am – – – – – – –
fewer left on time more left on time

The steadiest stretch at PWM was 8–10am — 91.6% of departures left on time across 1,200 flights. The weakest was 6–8pm at 72.5%. 6–8am departures from PWM left on time 91.2% of the time across 6,577 flights; 6–8pm departures, 72.5% across 1,841. That is a gap of 18.7 points, and it is the whole case for the early flight.

The year at PWM

July was the hard month at PWM: 73.2% of departures left on time, across 3,851 flights. November was the easy one at 87.4%. Each month pools three years of that month, so a single bad week does not decide it.

Share of departures that left on time, by calendar month. Best month in green, worst in amber. The hairline sits at the overall rate, 82.2%.
Departure on-time share at PWM by calendar month
Month Share departures that left on time Flights
January 82% 1,717
February 84.7% 1,573
March 83.9% 1,791
April 86.8% 2,119
May 85.1% 2,898
June 77.8% 3,625
July 73.2% 3,851
August 79.3% 4,025
September 85.8% 3,785
October 84.9% 3,655
November 87.4% 2,203
December 83% 1,986

Airlines at PWM

Every airline with at least 100 departures from PWM, busiest first. These are that airline’s departures from this airport only — its record across the country sits on its own page.

Airline Left on time Typical delay Cancelled Departures
Republic Airways 87.2% 88 min 3% 9,200
American Airlines 79.7% 127 min 1.8% 5,362
Southwest Airlines 78% 58 min 0.8% 4,684
Delta Air Lines 78.7% 79 min 1% 2,865
United Airlines 85.8% 103 min 1.7% 2,752
PSA Airlines 80.1% 120 min 4.4% 2,388
Endeavor Air 83.7% 102 min 3.9% 1,974
JetBlue Airways 78.4% 87 min 4.2% 1,367
SkyWest Airlines 80.8% 97 min 1.4% 1,192
Envoy Air 85% 71 min 1.8% 799
Frontier Airlines 74.3% 86 min 4.8% 645

Endeavor Air (through December 2024) stopped filing before June 2026. Its row covers a shorter run of months than the rest of the table, so its figure is not set against the others anywhere on this page.

What delays out of PWM were put down to

Airlines file a reason with every arrival running 15 minutes late or more. Across 6,357 flights that departed PWM and ran 15 minutes late or more, the delay minutes break down with 36% put down to airline operations and 33.3% to late-arriving aircraft.

Late-arriving aircraft 33.3% Airline operations 36% Air traffic & airport volume 23.4% Severe weather 7.3% Security 0.1%
  • Late-arriving aircraft 33.3%
  • Airline operations 36%
  • Air traffic & airport volume 23.4%
  • Severe weather 7.3%
  • Security 0.1%

Late-arriving aircraft is the knock-on category: the plane came in late, so it went out late again. It is why a 7am problem in Newark is still a problem in Denver at dinnertime, and why it is usually the biggest slice on the bar.

If you are connecting through PWM

Of 33,224 scheduled arrivals into PWM, 76.8% reached the gate less than 15 minutes behind schedule. Of the 6,885 arrivals that ran late, 54.9% were no more than 45 minutes behind — which is the difference between a tight connection and a new boarding pass.

Work out a specific layover — pick the airport and the minutes you have, and the tool reads the same arrival records back as a share.

Busiest routes out of PWM

Ranked by flights, with the share that arrived on time at the far end. Where a route carries enough flights for a page of its own the chip goes there; otherwise it goes to the destination airport.

PWM in one number

Portland Jetport (PWM)

Rank 97 of 363 US airports by departures. Steadiest stretch of the day: 8–10am. Hardest month: July.

July 2023–June 2026 · 32,442 departures flown

82.2% of departures left on time

Questions about PWM

What is the best time of day to fly out of Portland Jetport?
8–10am. Departures in that band left on time 91.6% of the time across 1,200 flights, July 2023 through June 2026 — the best of the ten bands in the day. The 6–8pm band was the weakest at 72.5%.
Is the early flight out of PWM really more reliable?
6–8am departures from PWM left on time 91.2% of the time across 6,577 flights; 6–8pm departures, 72.5% across 1,841. That is a gap of 18.7 points, and it is the whole case for the early flight.
What is the worst month to fly out of PWM?
July: 73.2% of the departures that flew left on time, with 3,851 scheduled. November was the other end of the year at 87.4%. Each figure pools three years of that calendar month.
Which airline is most on time at PWM?
Republic Airways — 87.2% of its 9,200 departures from PWM left on time. Frontier Airlines sat at the other end at 74.3% over 645 flights. Only airlines with at least 100 departures here are ranked. Airlines that stopped filing before June 2026 are left out of the ranking — their figures cover a shorter run of months than the rest of the table.
How often are flights cancelled at PWM?
2.4% of scheduled departures were cancelled over July 2023 through June 2026. Cancellations are counted against everything scheduled, not against everything that flew — a rate that looks small still adds up to real people in a rebooking line.