Measurements:
°C
°F
Nagasaki
38°F
SE 21 mph
Feels like: 28°F
Precip: 100%
World Resorts Japan Nagasaki Weather

Nagasaki Sea Water Temperature

Current Sea Water Temperature:
+63.8°F
Maximum Sea Water Temperature in January: 66.2°F
Minimum Sea Water Temperature in January: 58.6°F
Average water temperature in January: 61.8°F

Sea Water Temperature for the Last 10 Days:

January 10 63.8°F January 05 64.6°F
January 09 64.0°F January 04 65.0°F
January 08 64.2°F January 03 65.6°F
January 07 64.2°F January 02 65.2°F
January 06 64.0°F January 01 66.2°F

When is the Warmest Sea for Nagasaki?

According to our data for the last three years for Nagasaki 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 Nagasaki was 88.7°F. The maximum and minimum values were 86.6°F and 90.4°F respectively.

Sea Water Temperature in September

Select Year: 2025 2024 2023

The average sea surface temperature in September 2025 for Nagasaki was 87.7°F. The maximum and minimum values were 85.4°F and 89.2°F respectively.

Sea Water Temperature in July

Select Year: 2025 2024 2023

The average sea surface temperature in July 2025 for Nagasaki was 87.1°F. The maximum and minimum values were 84.2°F and 89.0°F respectively.

Best Time to Visit Nagasaki
The most sunny months:
October 18 days
May 14 days
March 13 days
The most warm months:
August 91.8 °F
July 88.3 °F
September 86.6 °F
Warmest sea temperature:
August 86.4 °F
September 83.7 °F
July 82.2 °F
The most cold months:
January 50.4 °F
February 51.9 °F
December 54.1 °F
The most rainy months:
July 12 days
June 11 days
August 10 days
The most windy months:
February 11 mph
January 11 mph
December 11 mph

Nagasaki on the Weather Map

Japan Resorts:
NAME
Atami +48
Fukuoka +36
Hakone +50
Hiroshima +32
Kamakura +54
Kyoto +36
Nagasaki +38
Nagoya +42
Nara +38
Noboribetsu +34
Okinawa +60
Osaka +40
Sapporo +32
Tokyo +52
Yokohama +54
24 Hours Weather Forecast
Nagasaki
Local time: 05:23
11 jan, sunday
0600 38°F
SE
21 mph
0900 38°F
SE
21 mph
1200 38°F
SE
20 mph
1500 40°F
SE
20 mph
1800 40°F
SE
22 mph
2100 38°F
SE
16 mph
12 jan, monday
0000 36°F
S
11 mph
0300 36°F
S
7 mph