Measurements:
°C
°F
Cayo Guillermo
88°F
W 19 mph
Feels like: 98°F
Precip: 14%
World Resorts Cuba Cayo Guillermo Weather

Cayo Guillermo Sea Water Temperature

Current Sea Water Temperature:
+89.6°F
Maximum Sea Water Temperature in July: 93.6°F
Minimum Sea Water Temperature in July: 86.0°F
Average water temperature in July: 89.2°F

Sea Water Temperature for the Last 10 Days:

July 12 89.6°F July 07 91.0°F
July 11 89.8°F July 06 91.2°F
July 10 89.8°F July 05 91.0°F
July 09 90.6°F July 04 91.4°F
July 08 91.6°F July 03 91.0°F

When is the Warmest Sea for Cayo Guillermo?

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

Average Water Temperature by Month, °F

Sea Water Temperature in September

Select Year: 2025 2024 2023

The average sea surface temperature in September 2025 for Cayo Guillermo was 91.4°F. The maximum and minimum values were 90.6°F and 92.6°F respectively.

Sea Water Temperature in August

Select Year: 2025 2024 2023

The average sea surface temperature in August 2025 for Cayo Guillermo was 91.0°F. The maximum and minimum values were 89.8°F and 92.8°F respectively.

Sea Water Temperature in July

Select Year: 2025 2024 2023

The average sea surface temperature in July 2025 for Cayo Guillermo was 89.2°F. The maximum and minimum values were 87.6°F and 90.2°F respectively.

Best Time to Visit Cayo Guillermo
The most sunny months:
April 14 days
March 13 days
May 12 days
The most warm months:
August 91.0 °F
July 90.5 °F
September 90.0 °F
Warmest sea temperature:
September 90.0 °F
August 89.9 °F
July 89.2 °F
The most cold months:
January 79.5 °F
February 80.4 °F
March 81.4 °F
The most rainy months:
October 7 days
May 6 days
August 6 days
The most windy months:
March 14 mph
November 14 mph
December 14 mph

Cayo Guillermo on the Weather Map

24 Hours Weather Forecast
Cayo Guillermo
Local time: 21:31
13 jul, monday
0000 88°F
W
20 mph
0300 88°F
W
17 mph
0600 86°F
W
17 mph
0900 86°F
W
17 mph
1200 88°F
W
17 mph
1500 88°F
W
17 mph
1800 88°F
W
18 mph
2100 86°F
W
19 mph