Measurements:
°C
°F
San Juan
78°F
W 11 mph
Feels like: 82°F
Precip: 78%
World Resorts Puerto Rico San Juan Weather

San Juan Sea Water Temperature

Current Sea Water Temperature:
+85.8°F
Maximum Sea Water Temperature in May: 88.4°F
Minimum Sea Water Temperature in May: 82.2°F
Average water temperature in May: 84.7°F

Sea Water Temperature for the Last 10 Days:

May 08 85.8°F May 03 85.6°F
May 07 86.0°F May 02 85.4°F
May 06 85.8°F May 01 85.4°F
May 05 85.8°F April 30 85.2°F
May 04 85.8°F April 29 85.0°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

Select Year: 2025 2024 2023

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

Select Year: 2025 2024 2023

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

Select Year: 2025 2024 2023

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.

Best Time to Visit San Juan
The most sunny months:
June 10 days
March 9 days
October 9 days
The most warm months:
September 91.1 °F
August 91.0 °F
July 90.6 °F
Warmest sea temperature:
October 88.8 °F
September 88.8 °F
August 87.8 °F
The most cold months:
February 84.0 °F
January 84.2 °F
March 84.7 °F
The most rainy months:
October 5 days
September 4 days
November 4 days
The most windy months:
July 12 mph
February 12 mph
June 12 mph

San Juan on the Weather Map

Puerto Rico Resorts:
NAME
Aguadilla +80
Arecibo +76
Isabella +78
Mayaguez +76
Ponce +74
San Juan +78
24 Hours Weather Forecast
San Juan
Local time: 02:01
09 may, saturday
0300 78°F
W
11 mph
0600 80°F
W
10 mph
0900 84°F
W
12 mph
1200 88°F
W
16 mph
1500 86°F
W
18 mph
1800 84°F
W
16 mph
2100 80°F
W
14 mph
10 may, sunday
0000 80°F
W
14 mph