Current Sea Water Temperature:
+86.6°F
| Maximum Sea Water Temperature in December: | 88.6°F |
| Minimum Sea Water Temperature in December: | 83.6°F |
| Average water temperature in December: | 85.7°F |
| detailed information | |
Sea Water Temperature for the Last 10 Days:
| December 15 | 86.6°F | December 10 | 86.4°F |
| December 14 | 86.4°F | December 09 | 86.8°F |
| December 13 | 86.8°F | December 08 | 86.6°F |
| December 12 | 86.6°F | December 07 | 86.6°F |
| December 11 | 86.4°F | December 06 | 86.8°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 October, September and August.
Average Water Temperature by Month, °F
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 September
The average sea surface temperature in September 2025 for San Juan was 89.7°F. The maximum and minimum values were 89.2°F and 90.4°F respectively.
Sea Water Temperature in August
The average sea surface temperature in August 2025 for San Juan was 88.7°F. The maximum and minimum values were 88.0°F and 89.2°F respectively.
Puerto Rico Resorts:
NAME
F°
| Aguadilla |  |
+72 |
| Arecibo | |
+74 |
| Isabella | |
+74 |
| Mayaguez | |
+76 |
| Ponce |  |
+76 |
| San Juan | |
+80 |
Countries:
NAME
POPULARITY
24 Hours Weather Forecast
San Juan
Local time: 04:08
15 dec, monday
| 0600 |  |
78°F | N 4 mph |
| 0900 |  |
82°F | NW 3 mph |
| 1200 |  |
84°F | W 9 mph |
| 1500 | |
86°F | W 11 mph |
| 1800 | |
84°F | W 10 mph |
| 2100 |  |
82°F | NW 8 mph |
16 dec, tuesday
| 0000 | |
80°F | NW 7 mph |
| 0300 | |
80°F | NW 6 mph |