Historical on-time performance
San Juan to Detroit
1,929 miData through May 2026Source: US DOT · BTS
Flights on SJU–DTW arrive on time 82% of the time over the last 12 months.
On-time rate82%arrived within 15 min
p90 delay30 min1 in 10 flights is worse (tail risk)
Cancelled1.7%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-time82%Medianon timep9030 minCancel1.7%Flights232
Why flights run late
Delay causes
- Airline12%
- Weather0%
- Air traffic (NAS)16%
- Late aircraft70%
- Security1%
Most delay minutes here are attributed to Late aircraft.
When flights don't go
Why flights were cancelled
- Airline50%
- Weather0%
- Air traffic (NAS)0%
- Security50%
Most cancellations here are attributed to Airline. Shares are among 4 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 SJU → DTW
All airlines · rolling 36 months (2023-06 .. 2026-05).
Best time of day
Middays are the most reliable time of day to fly this route — 90% on time.
- Middays90% on time · p90 10 min · 148 flights · limited
- Afternoons79% on time · p90 35 min · 1,021 flights
Best day of week
On-time rates are fairly even by day on this route — ranging from 77% to 86% on time.
- Tuesdays86% on time · p90 15 min · 151 flights · limited
- Wednesdays84% on time · p90 20 min · 155 flights · limited
- Mondays84% on time · p90 25 min · 182 flights · limited
- Thursdays80% on time · p90 35 min · 167 flights · limited
- Sundays79% on time · p90 40 min · 170 flights · limited
- Saturdays79% on time · p90 30 min · 214 flights
- Fridays77% on time · p90 40 min · 181 flights · limited
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