Measurements:
°C
°F
Guam
86°F
W 17 mph
Feels like: 96°F
Precip: 100%
World Resorts Northern Mariana Islands Guam Weather

Guam Sea Water Temperature

Current Sea Water Temperature:
+86.8°F
Maximum Sea Water Temperature in May: 90.8°F
Minimum Sea Water Temperature in May: 85.4°F
Average water temperature in May: 87.9°F

Sea Water Temperature for the Last 10 Days:

May 20 86.8°F May 15 87.2°F
May 19 87.0°F May 14 87.0°F
May 18 87.0°F May 13 86.8°F
May 17 87.0°F May 12 86.6°F
May 16 87.2°F May 11 85.8°F

When is the Warmest Sea for Guam?

According to our data for the last three years for Guam the highest average sea water temperature was in August, September and July.

Average Water Temperature by Month, °F

Sea Water Temperature in August

Select Year: 2025 2024 2023

The average sea surface temperature in August 2025 for Guam was 88.8°F. The maximum and minimum values were 87.8°F and 89.8°F respectively.

Sea Water Temperature in September

Select Year: 2025 2024 2023

The average sea surface temperature in September 2025 for Guam was 88.9°F. The maximum and minimum values were 87.8°F and 89.8°F respectively.

Sea Water Temperature in July

Select Year: 2025 2024 2023

The average sea surface temperature in July 2025 for Guam was 88.5°F. The maximum and minimum values were 87.4°F and 89.4°F respectively.

Best Time to Visit Guam
The most sunny months:
July 5 days
August 5 days
September 5 days
The most warm months:
June 91.6 °F
July 91.5 °F
August 91.1 °F
Warmest sea temperature:
August 89.4 °F
September 89.4 °F
July 89.2 °F
The most cold months:
February 86.8 °F
January 87.5 °F
March 87.8 °F
The most rainy months:
October 15 days
August 14 days
September 14 days
The most windy months:
February 17 mph
December 17 mph
January 16 mph

Guam on the Weather Map

Northern Mariana Islands Resorts:
NAME
Guam +86
Rota +86
Saipan +86
Susupe +86
Tinian +86
24 Hours Weather Forecast
Guam
Local time: 16:20
21 may, thursday
1800 86°F
W
14 mph
2100 84°F
W
14 mph
22 may, friday
0000 84°F
W
13 mph
0300 84°F
W
13 mph
0600 84°F
W
13 mph
0900 86°F
W
15 mph
1200 88°F
W
14 mph
1500 88°F
W
14 mph