Best Time to Fly JFK to SJU: On-Time Stats by Hour & Airline
John F. Kennedy International → Luis Munoz Marin International
Data through July 2026 · Last updated October 18, 2026
3,590 flights were scheduled from New York (JFK) to San Juan (SJU) in the last 12 months, and 70.1% of those that flew arrived on time, 7.5 points below the US average of 77.6%.
Delta Air Lines was the most punctual of the 3 airlines on the route at 77.3%, while Frontier Airlines trailed at 55.5%.
May has been the best month (83% on time) and Sunday the weakest day of the week (69%).
3.0% of flights were cancelled, versus 1.8% nationally.
JFK 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 |
|---|---|---|---|---|
| Delta Air Lines | 77.3% | 58 min | 2.3% | 1,104 |
| JetBlue | 68.2% | 77 min | 3.4% | 2,232 |
| Frontier Airlines | 55.5% | 108 min | 3.5% | 254 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly JFK to SJU
On-time arrival % by scheduled departure hour (local time), 7,733 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 83.8% | 2.8% | 400 |
| 6am–7am | 72.5% | 0.7% | 586 |
| 7am–8am | 83.8% | 2.3% | 171 |
| 8am–9am | 82.7% | 1.5% | 1,097 |
| 9am–10am | 75.4% | 1.5% | 203 |
| 10am–11am | 67.8% | 4.4% | 182 |
| 11am–12pm | 67.8% | 1.9% | 630 |
| 12pm–1pm | 83.5% | 0.6% | 914 |
| 1pm–2pm | 63.2% | 3.1% | 321 |
| 2pm–3pm | 75.2% | 3.5% | 226 |
| 3pm–4pm | 69.6% | 1.2% | 343 |
| 4pm–5pm | 68.2% | 1.8% | 110 |
| 5pm–6pm | 66.1% | 2.2% | 360 |
| 6pm–7pm | 60.4% | 3.4% | 466 |
| 7pm–8pm | 67.5% | 0.9% | 637 |
| 8pm–9pm | 60.6% | 3.4% | 352 |
| 9pm–10pm | 63.2% | 3.2% | 402 |
| 10pm–11pm | 67.2% | 2.0% | 296 |
| 11pm–12am | 70.3% | 0.0% | 37 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on JFK 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) | 68.5% | -6.9 pts | 1.2% | 161 |
| Christmas & New Year (Dec 20 - Jan 3) | 61.6% | -13.8 pts | 7.4% | 405 |
| Summer peak (Jun 15 - Aug 15) | 63.8% | -11.6 pts | 3.8% | 1,393 |
| All other days | 75.4% | — | 1.1% | 5,774 |
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).