Historical on-time performance
New York to San Juan
1,597 miData through May 2026Source: US DOT · BTS
Flights on JFK–SJU arrive on time 69% of the time over the last 12 months.
On-time rate69%arrived within 15 min
p90 delay60 min1 in 10 flights is worse (tail risk)
Cancelled2.6%of scheduled flights
based on 3,636 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).
By airline
How each carrier compares
- Delta Air LinesbestOn-time77%Medianon timep9040 minCancel2.0%Flights1,104
- JetBlue AirwaysOn-time67%Medianon timep9070 minCancel2.8%Flights2,232
- Frontier AirlinesOn-time51%Median10 minp9080 minCancel3.7%Flights300
Why flights run late
Delay causes
- Airline39%
- Weather2%
- Air traffic (NAS)26%
- Late aircraft33%
- Security1%
Most delay minutes here are attributed to Airline.
When flights don't go
Why flights were cancelled
- Airline14%
- Weather55%
- Air traffic (NAS)26%
- Security5%
Most cancellations here are attributed to Weather. Shares are among 96 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 JFK → 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 — 78% on time.
- Mornings78% on time · p90 35 min · 3,450 flights
- Middays72% on time · p90 65 min · 2,902 flights
- Afternoons70% on time · p90 70 min · 786 flights
- Evenings61% on time · p90 95 min · 1,950 flights
- Overnights56% on time · p90 100 min · 1,940 flights
Best day of week
On-time rates are fairly even by day on this route — ranging from 65% to 73% on time.
- Wednesdays73% on time · p90 55 min · 1,534 flights
- Fridays71% on time · p90 70 min · 1,605 flights
- Tuesdays71% on time · p90 55 min · 1,515 flights
- Mondays69% on time · p90 65 min · 1,596 flights
- Thursdays69% on time · p90 65 min · 1,587 flights
- Saturdays67% on time · p90 75 min · 1,591 flights
- Sundays65% on time · p90 85 min · 1,600 flights
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