ON TIMEBOARD

PWM → DTW on time

Portland Jetport (Portland, ME) to Detroit Metro (Detroit, MI). Every scheduled flight, September 2025 to August 2026.

On time
79%
arrived < 15 min late
Cancelled
1.1%
662 flights
Typical arrival
−11 min
median vs schedule
When late
+96 min
average delay
Flights / day
2
1 airline

79% of flights from Portland to Detroit arrived on time over the past 12 months. That is about the typical U.S. route. The noon departures ran on time 79% of the time; the 4 p.m. ones 79%. 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 PWM → DTW: 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 37 three hours or more; 1.1% were cancelled outright.

Share of all 662 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
Delta Air Lines66279%1.1%−11 min8.8%+96 minDelta Air Lines 61%, SkyWest 20%, Republic Airways 12%, Endeavor Air 7%

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 PWM). Delays build through the day as late planes knock on, so early flights usually do best.

40%70%100%noon departures: 79% on time (357 flights)7912p1 p.m. departures: too few flights (7 flights)1p2 p.m. departures: too few flights (1 flights)2p3 p.m. departures: too few flights3p4 p.m. departures: 79% on time (261 flights)794p5 p.m. departures: too few flights (21 flights)5p
PWM → DTW, 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 PWM → DTW, each airline's last flight of the day was cancelled 1.0% of the time, against 1.0% for its earlier flights, about the same. It arrived 3+ hours late 3.0% of the time (earlier flights: 2.7%). 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
Delta Air Lines4:47 p.m.1.0%3.0%1.0%first flight 12:40 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.

By month

Each calendar month pooled over 2023–2026. Best: April (91%). Worst: January (67%).

40%70%100%Jan: 67% on time (100 flights)67JanFeb: too few flights (85 flights)FebMar: 81% on time (139 flights)81MarApr: 91% on time (150 flights)91AprMay: 85% on time (155 flights)85MayJun: 77% on time (192 flights)77JunJul: 72% on time (206 flights)72JulAug: 79% on time (205 flights)79AugSep: 84% on time (204 flights)84SepOct: 83% on time (208 flights)83OctNov: 86% on time (191 flights)86NovDec: 74% on time (152 flights)74Dec

By day of week

DayFlightsOn timeCancelled
Monday97——
Tuesday95——
Wednesday93——
Thursday92——
Friday94——
Saturday95——
Sunday96——

Why flights were late

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

Airline (crew, maintenance, ops) 44%Late inbound plane 33%Severe weather 12%Air traffic & airport (NAS) 11%

Cancellations: airline 5 · weather 2

Month by month

Not enough months with data to draw a trend.

Questions

How often are flights from PWM to DTW on time?

79% of 662 scheduled flights from Portland, ME to Detroit, MI arrived within 15 minutes of schedule between September 2025 and August 2026. 1.1% were cancelled.

What is the best time of day to fly PWM to DTW?

Flights scheduled to leave at noon were the most reliable (79% on time). The 4 p.m. departures were the least (79%).

What month has the most delays from PWM to DTW?

January (67% on time). The best month is April (91%), over 2023–2026.

Is the last flight of the day from PWM to DTW more likely to be cancelled?

Not much. Each airline's last PWM–DTW flight of the day was cancelled 1.0% of the time over the past year, against 1.0% 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.