Airport reliability
Portland (PWM) on-time performance
How reliably flights leave Portland, ME (PWM) and reach their destinations, by airline, departure hour and month, September 2025 to August 2026.
Portland, ME10,917 departures in 12 months
- Departures on time
- 77.1% U.S. average 75.6%
- Cancelled
- 2.9% U.S. average 1.9%
- 60+ minutes late
- 7.3% U.S. average 8.1%
- Scheduled departures
- 10,917 12 months
What this means
PWM departures beat the U.S. average.
- 77.1% of the 10,917 scheduled departures from Portland (PWM) arrived at their destination on time, 1.5 points higher than the U.S. average of 75.6%.
- 2.9% of departures were cancelled (U.S. average 1.9%), and 7.3% arrived an hour or more late.
- Flights arriving at PWM were on time 75.5% of the time.
- Among airlines with at least 300 departures, Southwest Airlines was the most punctual from PWM (79.9%) and SkyWest Airlines the least (65.2%).
- Over the last 3 years, November was the most reliable month for departures from PWM (86.3% on time) and July the least reliable (68.6%).
- Cancellations peaked in January, when 6.3% of flights were cancelled.
- Flights scheduled to depart 8 am to 9 am were the most punctual (92.8% on time); flights scheduled to depart 5 pm to 6 pm were the least (62.2%).
Airlines at PWM
Ranked by on-time arrival
| Airline | On time | Cancelled | 60+ min late | Avg delay when late | Departures |
|---|---|---|---|---|---|
| Southwest Airlines | 79.9% | 0.8% | 4.0% | 56 min | 1,644 |
| Delta Air Lines | 79.6% | 0.9% | 6.6% | 103 min | 1,191 |
| Envoy AirSold as American Eagle | 78.6% | 4.1% | 7.1% | 97 min | 196 |
| Republic AirwaysSold as American Eagle, Delta Connection, United Express | 78.5% | 4.6% | 6.8% | 81 min | 3,567 |
| United Airlines | 76.9% | 1.0% | 8.2% | 87 min | 858 |
| American Airlines | 76.4% | 1.8% | 8.1% | 112 min | 2,010 |
| JetBlue Airways | 74.5% | 4.0% | 11.8% | 113 min | 423 |
| PSA AirlinesSold as American Eagle | 69.4% | 7.1% | 11.3% | 122 min | 637 |
| SkyWest AirlinesSold as United Express, Delta Connection, American Eagle, Alaska | 65.2% | 2.8% | 11.5% | 90 min | 391 |
Tap a heading to sort.
On-time rate by departure hour
Share of scheduled flights on time PWM average 77.1%
Show as table
| Period | On time | Flights |
|---|---|---|
| Departing before 6 am | 87.0% | 948 |
| Departing 6 am to 7 am | 85.8% | 1,661 |
| Departing 7 am to 8 am | 85.2% | 732 |
| Departing 8 am to 9 am | 92.8% | 235 |
| Departing 9 am to 10 am | 86.3% | 380 |
| Departing 10 am to 11 am | 81.6% | 505 |
| Departing 11 am to noon | 82.1% | 547 |
| Departing noon to 1 pm | 77.2% | 995 |
| Departing 1 pm to 2 pm | 72.8% | 569 |
| Departing 2 pm to 3 pm | 69.4% | 778 |
| Departing 3 pm to 4 pm | 70.5% | 911 |
| Departing 4 pm to 5 pm | 70.2% | 786 |
| Departing 5 pm to 6 pm | 62.2% | 1,090 |
| Departing 6 pm to 7 pm | 65.5% | 339 |
| Departing 7 pm to 8 pm | 75.8% | 360 |
| Departing 8 pm to 9 pm | 64.2% | 81 |
Best and worst months at PWM
Share of scheduled flights on time 12-month average 77.1%
Show as table
| Period | On time | Flights |
|---|---|---|
| January | 72.8% | 1,717 |
| February | 80.0% | 1,573 |
| March | 79.1% | 1,791 |
| April | 82.2% | 2,119 |
| May | 81.8% | 2,898 |
| June | 74.3% | 3,625 |
| July | 68.6% | 3,889 |
| August | 72.7% | 4,075 |
| September | 82.5% | 3,785 |
| October | 84.1% | 3,655 |
| November | 86.3% | 2,203 |
| December | 79.5% | 1,986 |
Month by month, last 12 months
Share of scheduled flights on time U.S. average 75.6%
Show as table
| Period | On time | Flights |
|---|---|---|
| Sep 2025 | 84.7% | 1,202 |
| Oct 2025 | 80.7% | 1,266 |
| Nov 2025 | 79.4% | 656 |
| Dec 2025 | 71.1% | 546 |
| Jan 2026 | 68.5% | 556 |
| Feb 2026 | 78.3% | 521 |
| Mar 2026 | 71.1% | 641 |
| Apr 2026 | 81.2% | 720 |
| May 2026 | 84.8% | 1,056 |
| Jun 2026 | 79.4% | 1,201 |
| Jul 2026 | 70.6% | 1,251 |
| Aug 2026 | 70.0% | 1,301 |
Busiest routes from PWM
| To | On time | Cancelled | Airlines | Flights |
|---|---|---|---|---|
| Chicago (ORD) | 74.9% | 3.4% | 5 | 1,493 |
| Baltimore (BWI) | 80.4% | 0.9% | 1 | 1,331 |
| New York (LGA) | 76.3% | 4.7% | 3 | 1,230 |
| Washington (DCA) | 70.1% | 4.3% | 3 | 1,143 |
| Newark (EWR) | 79.0% | 4.7% | 2 | 1,080 |
| Charlotte (CLT) | 80.5% | 1.1% | 2 | 708 |
| Washington (IAD) | 83.1% | 2.7% | 2 | 692 |
| Philadelphia (PHL) | 76.2% | 4.3% | 3 | 667 |
| Atlanta (ATL) | 78.1% | 1.0% | 1 | 631 |
| Detroit (DTW) | 79.3% | 0.8% | 3 | 614 |
| New York (JFK) | 74.9% | 5.6% | 2 | 390 |
| Denver (DEN) | 69.2% | 0.0% | 1 | 211 |
| Nashville (BNA) | 67.9% | 0.6% | 1 | 159 |
| Chicago (MDW) | 88.1% | 0.0% | 1 | 151 |
| Dallas/Fort Worth (DFW) | 79.9% | 2.1% | 1 | 144 |
| Minneapolis (MSP) | 83.9% | 0.0% | 1 | 143 |
| Orlando (MCO) | 72.7% | 1.1% | 2 | 88 |
Sources & data dates
- Source
- U.S. DOT Bureau of Transportation Statistics, Reporting Carrier On-Time Performance (1987-present)
- Period
- September 2025 to August 2026 (12 months); month-of-year patterns September 2023 to August 2026
- Data through
- August 2026
- Processed
- 2026-11-03
- Scope
- Scheduled nonstop domestic departures from Portland, ME (PWM) by airlines that report to the DOT.
- Method
- Rates use all scheduled flights as the denominator; cancelled and diverted flights count as not on time. Figures based on fewer than 50 scheduled flights are suppressed. Full methodology.