OnTimeStats

Historical on-time performance

Boston to Portland

2,537 miData through May 2026Source: US DOT · BTS

Flights on BOS–PDX arrive on time 74% of the time over the last 12 months.

On-time rate74%arrived within 15 min
p90 delay45 min1 in 10 flights is worse (tail risk)
Cancelled1.0%of scheduled flights

based on 603 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

Not enough comparable data to name a most-on-time carrier — low-data carriers aren't ranked.

  • Alaska Airlines
    On-time77%
    Medianon time
    p9035 min
    Cancel1.0%
    Flights511
  • JetBlue Airways
    On-time55%
    Median5 min
    p90105 min
    Cancel1.1%
    Flights92

Why flights run late

Delay causes

  • Airline24%
  • Weather1%
  • Air traffic (NAS)30%
  • Late aircraft45%
  • Security0%

Most delay minutes here are attributed to Late aircraft.

When flights don't go

Why flights were cancelled

  • Airline50%
  • Weather33%
  • Air traffic (NAS)17%
  • Security0%

Most cancellations here are attributed to Airline. Shares are among 6 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 BOS → PDX

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 — 85% on time.

  • Mornings85% on time · p90 20 min · 551 flights
  • Evenings68% on time · p90 65 min · 1,171 flights
  • Afternoons66% on time · p90 45 min · 101 flights · limited

Best day of week

On-time rates are fairly even by day on this route — ranging from 68% to 80% on time.

  • Saturdays80% on time · p90 30 min · 247 flights
  • Wednesdays80% on time · p90 35 min · 253 flights
  • Tuesdays77% on time · p90 40 min · 255 flights
  • Mondays72% on time · p90 50 min · 295 flights
  • Sundays71% on time · p90 50 min · 274 flights
  • Fridays70% on time · p90 65 min · 301 flights
  • Thursdays68% on time · p90 65 min · 280 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.