Current Sea Water Temperature:
+90.0°F
| Maximum Sea Water Temperature in September: | 92.0°F |
| Minimum Sea Water Temperature in September: | 86.2°F |
| Average water temperature in September: | 88.8°F |
| detailed information | |
Sea Water Temperature for the Last 10 Days:
| September 28 | 90.0°F | September 23 | 89.8°F |
| September 27 | 90.0°F | September 22 | 89.6°F |
| September 26 | 90.0°F | September 21 | 89.8°F |
| September 25 | 90.2°F | September 20 | 89.2°F |
| September 24 | 90.0°F | September 19 | 89.8°F |
When is the Warmest Sea for San Juan?
According to our data for the last three years for San Juan the highest average sea water temperature was in September, October and August.
Average Water Temperature by Month, °F
Sea Water Temperature in September
The average sea surface temperature in September 2026 for San Juan was 89.3°F. The maximum and minimum values were 88.0°F and 90.2°F respectively.
Sea Water Temperature in October
The average sea surface temperature in October 2025 for San Juan was 89.5°F. The maximum and minimum values were 88.6°F and 90.0°F respectively.
Sea Water Temperature in August
The average sea surface temperature in August 2026 for San Juan was 88.4°F. The maximum and minimum values were 87.6°F and 89.4°F respectively.
Puerto Rico Resorts:
NAME
F°
| Aguadilla |  |
+88 |
| Arecibo |  |
+86 |
| Isabella | |
+84 |
| Mayaguez | |
+88 |
| Ponce | |
+88 |
| San Juan |  |
+88 |
Countries:
NAME
POPULARITY
24 Hours Weather Forecast
San Juan
Local time: 17:12
28 sep, monday
| 1800 |  |
88°F | W 14 mph |
| 2100 |  |
86°F | W 11 mph |
29 sep, tuesday
| 0000 | |
86°F | W 12 mph |
| 0300 | |
86°F | W 10 mph |
| 0600 | |
84°F | W 9 mph |
| 0900 | |
88°F | W 12 mph |
| 1200 |  |
90°F | W 14 mph |
| 1500 | |
90°F | W 15 mph |