Historical on-time performance
Detroit to San Juan
1,929 miData through May 2026Source: US DOT · BTS
Flights on DTW–SJU arrive on time 73% of the time over the last 12 months.
On-time rate73%arrived within 15 min
p90 delay35 min1 in 10 flights is worse (tail risk)
Cancelled1.3%of scheduled flights
based on 232 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).
By airline
How each carrier compares
- Delta Air LinesOn-time73%Medianon timep9035 minCancel1.3%Flights232
Why flights run late
Delay causes
- Airline41%
- Weather4%
- Air traffic (NAS)45%
- Late aircraft10%
- Security0%
Most delay minutes here are attributed to Air traffic (NAS).
When flights don't go
Why flights were cancelled
- Airline33%
- Weather0%
- Air traffic (NAS)0%
- Security67%
Most cancellations here are attributed to Security. Shares are among 3 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 DTW → SJU
All airlines · rolling 36 months (2023-06 .. 2026-05).
Best day of week
On-time rates are fairly even by day on this route — ranging from 73% to 85% on time.
- Tuesdays85% on time · p90 20 min · 151 flights · limited
- Wednesdays83% on time · p90 20 min · 155 flights · limited
- Sundays82% on time · p90 35 min · 170 flights · limited
- Saturdays80% on time · p90 25 min · 214 flights
- Fridays79% on time · p90 30 min · 181 flights · limited
- Thursdays73% on time · p90 35 min · 166 flights · limited
- Mondays73% on time · p90 35 min · 182 flights · limited
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