Measurements:
°C
°F
Kauai
70°F
W 9 mph
Feels like: 70°F
Precip: 73%
World Resorts USA Kauai Weather

Kauai Sea Water Temperature

Current Sea Water Temperature:
+77.8°F
Maximum Sea Water Temperature in April: 80.8°F
Minimum Sea Water Temperature in April: 77.0°F
Average water temperature in April: 78.7°F

Sea Water Temperature for the Last 10 Days:

April 03 77.8°F March 29 78.6°F
April 02 77.8°F March 28 78.6°F
April 01 77.8°F March 27 78.8°F
March 31 78.0°F March 26 79.0°F
March 30 78.2°F March 25 79.6°F

When is the Warmest Sea for Kauai?

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

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 Kauai was 85.0°F. The maximum and minimum values were 84.6°F and 85.4°F respectively.

Sea Water Temperature in October

Select Year: 2025 2024 2023

The average sea surface temperature in October 2025 for Kauai was 84.8°F. The maximum and minimum values were 83.8°F and 85.4°F respectively.

Sea Water Temperature in August

Select Year: 2025 2024 2023

The average sea surface temperature in August 2025 for Kauai was 82.3°F. The maximum and minimum values were 79.0°F and 84.8°F respectively.

Best Time to Visit Kauai
The most sunny months:
January 6 days
December 5 days
February 4 days
The most warm months:
September 83.7 °F
August 83.4 °F
July 82.5 °F
Warmest sea temperature:
September 83.9 °F
October 83.8 °F
August 82.9 °F
The most cold months:
February 76.2 °F
March 76.9 °F
January 77.4 °F
The most rainy months:
January 2 days
March 2 days
February 2 days
The most windy months:
July 11 mph
June 11 mph
May 11 mph

Kauai on the Weather Map

USA Resorts:
NAME
Chicago +46
Hawaii +74
Honolulu +74
Houston +74
Las Vegas +54
Los Angeles +56
Maui +66
Miami +74
Miami Beach +78
New York +40
San Diego +58
San Francisco +50
Sarasota +72
Tampa +72
Washington +48
24 Hours Weather Forecast
Kauai
Local time: 23:49
03 apr, friday
0000 70°F
W
9 mph
0300 70°F
W
8 mph
0600 68°F
W
9 mph
0900 74°F
W
9 mph
1200 76°F
W
11 mph
1500 76°F
W
12 mph
1800 72°F
W
9 mph
2100 70°F
W
9 mph