Best Time to Fly DTW to SJU: On-Time Stats by Hour & Airline
Detroit Metro Wayne County → Luis Munoz Marin International
Data through July 2026 · Last updated October 18, 2026
358 flights were scheduled from Detroit (DTW) to San Juan (SJU) in the last 12 months, and 75.9% of those that flew arrived on time, 1.7 points below the US average of 77.6%.
Among 2 airlines, Spirit Airlines led with 79.4% on time and Delta Air Lines was last with 75.5%.
Over 24 months, Tuesday was the most reliable day (82% on time) and January the worst month (58%).
The cancellation rate was 0.8% (US average 1.8%).
DTW to SJU on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| Spirit Airlines | 79.4% | 52 min | 0.0% | 34 |
| Delta Air Lines | 75.5% | 47 min | 0.9% | 324 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly DTW to SJU
On-time arrival % by scheduled departure hour (local time), 733 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | Limited data | 15 | |
| 7am–8am | 84.1% | 0.0% | 44 |
| 8am–9am | 77.8% | 0.2% | 526 |
| 9am–10am | 79.2% | 1.0% | 98 |
| 10am–11am | 63.6% | 2.2% | 45 |
| 11am–12pm | Limited data | 4 | |
| 6pm–7pm | Limited data | 1 | |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on DTW to SJU
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | Limited data | 13 | ||
| Christmas & New Year (Dec 20 - Jan 3) | 67.2% | -10.6 pts | 3.3% | 60 |
| Summer peak (Jun 15 - Aug 15) | 81.0% | +3.1 pts | 0.0% | 168 |
| All other days | 77.9% | — | 0.2% | 492 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).