Measurements:
°C
°F
Kauai
82°F
W 15 mph
Feels like: 86°F
Precip: 20%
World Resorts USA Kauai Weather

Kauai Sea Water Temperature

Current Sea Water Temperature:
+84.2°F
Maximum Sea Water Temperature in August: 84.8°F
Minimum Sea Water Temperature in August: 79.0°F
Average water temperature in August: 83.1°F

Sea Water Temperature for the Last 10 Days:

August 25 84.2°F August 20 83.4°F
August 24 84.0°F August 19 83.4°F
August 23 84.0°F August 18 83.0°F
August 22 83.8°F August 17 82.6°F
August 21 83.6°F August 16 83.2°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: 2026 2025 2024

The average sea surface temperature in August 2026 for Kauai was 83.8°F. The maximum and minimum values were 82.6°F and 84.4°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
October 82.4 °F
Warmest sea temperature:
September 83.9 °F
October 83.8 °F
August 83.0 °F
The most cold months:
February 76.2 °F
March 76.9 °F
January 77.4 °F
The most rainy months:
March 2 days
January 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
Boston +80
Chicago +80
Hawaii +84
Houston +106
Las Vegas +116
Los Angeles +96
Maui +70
Miami +92
Myrtle Beach +84
New York +82
San Diego +96
San Francisco +64
Santa Monica +86
Sarasota +92
Washington +84
24 Hours Weather Forecast
Kauai
Local time: 11:36
25 aug, tuesday
1200 82°F
W
15 mph
1500 84°F
W
12 mph
1800 80°F
W
12 mph
2100 78°F
W
9 mph
26 aug, wednesday
0000 78°F
W
10 mph
0300 76°F
W
11 mph
0600 76°F
W
11 mph
0900 80°F
W
13 mph