OnTimeStats

Historical on-time performance

Miami to Boston

1,258 miData through May 2026Source: US DOT · BTS

Flights on MIA–BOS arrive on time 68% of the time over the last 12 months.

On-time rate68%arrived within 15 min
p90 delay70 min1 in 10 flights is worse (tail risk)
Cancelled2.4%of scheduled flights

based on 3,359 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.

  • American Airlines
    On-time69%
    Medianon time
    p9065 min
    Cancel1.9%
    Flights2,212
  • Delta Air Lines
    On-time67%
    Medianon time
    p9075 min
    Cancel2.9%
    Flights886
  • JetBlue Airways
    On-time66%
    Medianon time
    p9080 min
    Cancel3.8%
    Flights132
  • Spirit Airlines
    On-time44%
    Median15 min
    p90100 min
    Cancel7.0%
    Flights129

Why flights run late

Delay causes

  • Airline32%
  • Weather3%
  • Air traffic (NAS)22%
  • Late aircraft42%
  • Security0%

Most delay minutes here are attributed to Late aircraft.

When flights don't go

Why flights were cancelled

  • Airline17%
  • Weather76%
  • Air traffic (NAS)7%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 82 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 MIA → BOS

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 — 87% on time.

  • Mornings87% on time · p90 15 min · 1,952 flights
  • Middays71% on time · p90 60 min · 3,326 flights
  • Afternoons64% on time · p90 85 min · 1,358 flights
  • Overnights62% on time · p90 85 min · 1,984 flights
  • Evenings59% on time · p90 85 min · 2,602 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 61% to 73% on time.

  • Wednesdays73% on time · p90 55 min · 1,531 flights
  • Tuesdays72% on time · p90 60 min · 1,561 flights
  • Saturdays71% on time · p90 60 min · 1,622 flights
  • Mondays69% on time · p90 70 min · 1,613 flights
  • Fridays68% on time · p90 70 min · 1,623 flights
  • Thursdays68% on time · p90 75 min · 1,615 flights
  • Sundays61% on time · p90 85 min · 1,657 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.