OnTimeStats

Historical on-time performance

Baltimore to San Juan

1,565 miData through May 2026Source: US DOT · BTS

Flights on BWI–SJU arrive on time 68% of the time over the last 12 months.

On-time rate68%arrived within 15 min
p90 delay50 min1 in 10 flights is worse (tail risk)
Cancelled1.3%of scheduled flights

based on 917 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.

  • Southwest Airlines
    On-time69%
    Medianon time
    p9050 min
    Cancel0.8%
    Flights825
  • Spirit Airlines
    On-time64%
    Medianon time
    p9050 min
    Cancel5.4%
    Flights92

Why flights run late

Delay causes

  • Airline31%
  • Weather3%
  • Air traffic (NAS)28%
  • Late aircraft37%
  • Security1%

Most delay minutes here are attributed to Late aircraft.

When flights don't go

Why flights were cancelled

  • Airline8%
  • Weather67%
  • Air traffic (NAS)25%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 12 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 BWI → SJU

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 — 75% on time.

  • Mornings75% on time · p90 35 min · 1,300 flights
  • Middays66% on time · p90 65 min · 477 flights
  • Afternoons65% on time · p90 70 min · 230 flights
  • Evenings62% on time · p90 65 min · 1,145 flights
  • Overnights57% on time · p90 100 min · 863 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 45 min · 535 flights
  • Tuesdays72% on time · p90 45 min · 489 flights
  • Fridays67% on time · p90 75 min · 593 flights
  • Thursdays66% on time · p90 55 min · 540 flights
  • Sundays63% on time · p90 60 min · 610 flights
  • Saturdays62% on time · p90 60 min · 659 flights
  • Mondays61% on time · p90 80 min · 589 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.