Detroit (DTW) to San Juan (SJU): On-Time Performance
Data through July 2026
Detroit (DTW) to San Juan (SJU) is a thinner route than most in this dataset — 358 departures over the past year, roughly 7 a week — so treat these numbers as indicative rather than definitive. Of the flights that did operate, 77% arrived on time.
- On-time
- 77%
- arrived <15 min late
- Avg delay
- 13 min
- completed flights
- Cancelled
- 0.4%
- Flights/day
- 0.98
- last 12 months
- Duration
- 4h 24m
- scheduled
- Distance
- 1,930 mi
Best airline from DTW to SJU
2 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Spirit Airlinesmost reliable | 81% | 11 min | 0.0% | 72 |
| Delta Air Lines | 77% | 14 min | 0.4% | 692 |
Monthly on-time trend
Best time to fly from DTW to SJU
Aim for departures around 7 a.m. (84% on-time); avoid 10 a.m. departures (64%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 72% | 11 min |
| Tuesdaybest | 83% | 8 min |
| Wednesday | 81% | 11 min |
| Thursday | 71% | 14 min |
| Friday | 76% | 21 min |
| Saturday | 79% | 12 min |
| Sunday | 79% | 16 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft5%
- Airline operations50%
- National airspace system44%
- Weather2%
Frequently asked questions
- How often are flights from DTW to SJU delayed?
- 23% of DTW–SJU flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-07 and 2026-07. The average arrival delay across completed flights was 13 minutes.
- Which airline is most reliable from DTW to SJU?
- Spirit Airlines has the best on-time record on this route at 81%, based on 72 flights. 2 airlines flew DTW–SJU frequently enough to compare in this period.
- What is the best time of day to fly from DTW to SJU?
- Departures around 7 a.m. have the best record (84% on-time), while departures around 10 a.m. have the worst (64%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from DTW to SJU?
- The scheduled DTW–SJU flight time averages 4h 24m over 1,930 miles. Actual arrival times vary — flights on this route land 15+ minutes late 23% of the time.
- How often are DTW to SJU flights cancelled?
- 0.4% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, at or below the national rate of 1.6%.
- What is the worst month to fly from DTW to SJU?
- January 2026 was the roughest month in this dataset, with only 56% of arrivals on time. The best was July 2026 at 87%. If your dates are flexible, that 31-point gap is worth planning around.
Explore related pages
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Related guides
Based on 764 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.