OnTimeStats

Historical on-time performance

Portland to Atlanta

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

Flights on PWM–ATL arrive on time 77% of the time over the last 12 months.

On-time rate77%arrived within 15 min
p90 delay45 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-time77%
    Medianon time
    p9045 min
    Cancel1.1%
    Flights613

Why flights run late

Delay causes

  • Airline67%
  • Weather4%
  • Air traffic (NAS)13%
  • Late aircraft16%
  • 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 PWM → ATL

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

Best time of day

Mornings are the most reliable time of day to fly this route — 86% on time.

  • Mornings86% on time · p90 15 min · 1,096 flights
  • Middays70% on time · p90 60 min · 360 flights
  • Afternoons62% on time · p90 65 min · 167 flights · limited

Best day of week

On-time rates are fairly even by day on this route — ranging from 74% to 85% on time.

  • Wednesdays85% on time · p90 25 min · 239 flights
  • Fridays83% on time · p90 35 min · 241 flights
  • Thursdays80% on time · p90 25 min · 241 flights
  • Tuesdays79% on time · p90 40 min · 238 flights
  • Saturdays77% on time · p90 60 min · 255 flights
  • Sundays75% on time · p90 45 min · 242 flights
  • Mondays74% on time · p90 35 min · 239 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.