OnTimeStats

Historical on-time performance

Portland to Boston

2,537 miData through Dec 2025Source: US DOT · BTS

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

On-time rate74%arrived within 15 min
p90 delay35 min1 in 10 flights is worse (tail risk)
Cancelled0.4%of scheduled flights

based on 552 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • Alaska Airlinesbest
    On-time78%
    Medianon time
    p9025 min
    Cancel0.2%
    Flights429
  • JetBlue Airways
    On-time58%
    Median5 min
    p9080 min
    Cancel0.8%
    Flights123

Why flights run late

Delay causes

  • Airline30%
  • Weather0%
  • Air traffic (NAS)36%
  • Late aircraft34%
  • Security0%

Most delay minutes here are attributed to Air traffic (NAS).

Over time

On-time trend

By season

On-time rate by month

When to fly

Best time to fly PDX → BOS

All airlines · rolling 36 months (2023-01 .. 2025-12).

Best time of day

Mornings are the most reliable time of day to fly this route — 81% on time.

  • Mornings81% on time · p90 30 min · 740 flights
  • Middays71% on time · p90 60 min · 382 flights
  • Overnights69% on time · p90 60 min · 706 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 70% to 77% on time.

  • Sundays77% on time · p90 45 min · 291 flights
  • Wednesdays76% on time · p90 40 min · 262 flights
  • Saturdays75% on time · p90 35 min · 212 flights
  • Tuesdays74% on time · p90 45 min · 235 flights
  • Mondays74% on time · p90 45 min · 290 flights
  • Fridays71% on time · p90 75 min · 292 flights
  • Thursdays70% on time · p90 50 min · 289 flights
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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.