Measurements:
°C
°F
Nagasaki
78°F
NE 13 mph
Feels like: 82°F
Precip: 71%
World Resorts Japan Nagasaki Weather

Nagasaki Sea Water Temperature

Current Sea Water Temperature:
+74.0°F
Maximum Sea Water Temperature in May: 74.0°F
Minimum Sea Water Temperature in May: 63.8°F
Average water temperature in May: 68.7°F

Sea Water Temperature for the Last 10 Days:

May 19 74.0°F May 14 70.4°F
May 18 73.0°F May 13 69.0°F
May 17 71.8°F May 12 69.2°F
May 16 72.2°F May 11 67.4°F
May 15 71.4°F May 10 68.4°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
August 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 52.0 °F
December 54.1 °F
The most rainy months:
July 12 days
June 11 days
August 10 days
The most windy months:
January 11 mph
February 11 mph
December 11 mph

Nagasaki on the Weather Map

Japan Resorts:
NAME
Atami +80
Fukuoka +80
Hakone +78
Hiroshima +70
Kamakura +74
Kobe +74
Kyoto +74
Nagasaki +78
Nagoya +82
Nara +76
Okinawa +80
Osaka +76
Sapporo +64
Tokyo +86
Yokohama +76
24 Hours Weather Forecast
Nagasaki
Local time: 14:27
20 may, wednesday
1500 78°F
NE
13 mph
1800 74°F
N
9 mph
2100 74°F
N
9 mph
21 may, thursday
0000 74°F
N
12 mph
0300 72°F
N
20 mph
0600 72°F
NE
18 mph
0900 72°F
NE
19 mph
1200 72°F
NE
14 mph