OnTimeStats

Historical on-time performance

San Diego to Boston

2,588 miData through May 2026Source: US DOT · BTS

Flights on SAN–BOS arrive on time 76% of the time over the last 12 months.

On-time rate76%arrived within 15 min
p90 delay45 min1 in 10 flights is worse (tail risk)
Cancelled1.4%of scheduled flights

based on 1,674 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

Too close to call — no single carrier is clearly more on-time here.

  • JetBlue Airways
    On-time78%
    Medianon time
    p9055 min
    Cancel1.3%
    Flights915
  • Delta Air Lines
    On-time77%
    Medianon time
    p9030 min
    Cancel1.3%
    Flights307
  • Alaska Airlines
    On-time72%
    Medianon time
    p9055 min
    Cancel1.8%
    Flights452

Why flights run late

Delay causes

  • Airline27%
  • Weather9%
  • Air traffic (NAS)33%
  • Late aircraft30%
  • Security0%

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

When flights don't go

Why flights were cancelled

  • Airline46%
  • Weather46%
  • Air traffic (NAS)8%
  • Security0%

Most cancellations here are attributed to Airline. Shares are among 24 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 SAN → BOS

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

Best time of day

Overnights are the most reliable time of day to fly this route — 80% on time.

  • Overnights80% on time · p90 35 min · 2,352 flights
  • Mornings73% on time · p90 60 min · 942 flights
  • Afternoons73% on time · p90 65 min · 226 flights
  • Middays67% on time · p90 65 min · 1,276 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 70% to 79% on time.

  • Tuesdays79% on time · p90 40 min · 677 flights
  • Saturdays78% on time · p90 35 min · 571 flights
  • Wednesdays77% on time · p90 40 min · 696 flights
  • Mondays75% on time · p90 50 min · 716 flights
  • Fridays73% on time · p90 60 min · 721 flights
  • Thursdays71% on time · p90 60 min · 707 flights
  • Sundays70% on time · p90 60 min · 716 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.