OnTimeStats

Historical on-time performance

Atlanta to Portland

1,027 miData through May 2026Source: US DOT · BTS

Flights on ATL–PWM arrive on time 74% of the time over the last 12 months.

On-time rate74%arrived within 15 min
p90 delay50 min1 in 10 flights is worse (tail risk)
Cancelled1.1%of scheduled flights

based on 613 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • Delta Air Lines
    On-time74%
    Medianon time
    p9050 min
    Cancel1.1%
    Flights613

Why flights run late

Delay causes

  • Airline44%
  • Weather7%
  • Air traffic (NAS)17%
  • Late aircraft33%
  • Security0%

Most delay minutes here are attributed to Airline.

When flights don't go

Why flights were cancelled

  • Airline29%
  • Weather71%
  • Air traffic (NAS)0%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 7 cancellations with a reported cause (BTS reports causes from June 2003).

Over time

On-time trend

By season

On-time rate by month

When to fly

Best time to fly ATL → PWM

All airlines · rolling 36 months (2023-06 .. 2026-05).

Best time of day

On-time rates are fairly even by time of day on this route — ranging from 75% to 86% on time.

  • Middays86% on time · p90 20 min · 220 flights
  • Mornings81% on time · p90 20 min · 313 flights
  • Overnights79% on time · p90 35 min · 775 flights
  • Evenings75% on time · p90 45 min · 317 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 68% to 83% on time.

  • Mondays83% on time · p90 30 min · 239 flights
  • Wednesdays82% on time · p90 25 min · 239 flights
  • Tuesdays82% on time · p90 30 min · 238 flights
  • Thursdays80% on time · p90 30 min · 241 flights
  • Fridays79% on time · p90 35 min · 241 flights
  • Saturdays78% on time · p90 40 min · 255 flights
  • Sundays68% on time · p90 50 min · 242 flights

Keep exploring

Related pages

Methodology

A flight is on time when it arrives within 15 minutes of schedule — the US DOT / BTS standard. Median and p90(the “1-in-10 bad day”) are read from the full arrival-delay distribution, never averaged across periods.

Figures cover a carrier’s own BTS-coded flights. Cells below ~200 flights are flagged as limited data. All numbers are pre-computed from public BTS On-Time Performance data.