Best Time to Fly ATL to SJU: On-Time Stats by Hour & Airline
Hartsfield-Jackson Atlanta International → Luis Munoz Marin International
Data through July 2026 · Last updated October 18, 2026
2,099 flights were scheduled from Atlanta (ATL) to San Juan (SJU) in the last 12 months, and 70.9% of those that flew arrived on time, 6.7 points below the US average of 77.6%.
Among 3 airlines, Delta Air Lines led with 76.5% on time and Spirit Airlines was last with 35.6%.
Over 24 months, Wednesday was the most reliable day (82% on time) and March the worst month (67%).
The cancellation rate was 1.3% (US average 1.8%).
ATL 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 | 76.5% | 52 min | 0.9% | 1,627 |
| Frontier Airlines | 55.0% | 70 min | 1.9% | 379 |
| Spirit Airlines | 35.6% | 59 min | 6.5% | 93 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly ATL to SJU
On-time arrival % by scheduled departure hour (local time), 4,223 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | 83.6% | 0.0% | 55 |
| 7am–8am | 86.0% | 1.0% | 101 |
| 8am–9am | 86.8% | 0.5% | 734 |
| 9am–10am | 75.4% | 0.7% | 422 |
| 10am–11am | 63.6% | 1.4% | 716 |
| 11am–12pm | 63.3% | 1.0% | 99 |
| 12pm–1pm | 81.4% | 0.8% | 352 |
| 1pm–2pm | 82.0% | 0.9% | 421 |
| 2pm–3pm | Limited data | 2 | |
| 3pm–4pm | Limited data | 14 | |
| 4pm–5pm | 59.1% | 0.9% | 449 |
| 5pm–6pm | Limited data | 7 | |
| 6pm–7pm | 71.9% | 1.2% | 423 |
| 7pm–8pm | 57.2% | 1.3% | 308 |
| 8pm–9pm | 51.4% | 1.4% | 73 |
| 9pm–10pm | 63.0% | 2.1% | 47 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on ATL 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) | 74.3% | +1.2 pts | 1.4% | 72 |
| Christmas & New Year (Dec 20 - Jan 3) | 70.6% | -2.5 pts | 5.3% | 243 |
| Summer peak (Jun 15 - Aug 15) | 71.5% | -1.6 pts | 0.8% | 753 |
| All other days | 73.1% | — | 0.7% | 3,155 |
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).