Nagasaki features a humid subtropical climate with four distinct seasons, mild winters, and hot, humid summers. The city is one of Japan’s wettest, with significant rainfall peaking in early summer and during typhoon season. Despite the rain, Nagasaki enjoys many sunny days, and its coastal location keeps winter temperatures milder than much of Japan.
The best times to travel section shows how the months compare for a visit, so you can find the time of year that fits what you want to do.
Background colours of the months:
The colour shows the typical temperature: yellow (hot), green (mild) and blue (cold). How strong the colour is shows the travel season: full colour means high season, soft colour means shoulder season and soft-striped means off season.
Weather symbols:
Each month has one symbol showing what the weather is typically like, such as hot and sunny, freezing or a rainy or snowy season. Use them to quickly spot months that match the weather you want, or to avoid the ones that don't.
Crowdedness:
The people icon shows how busy the place usually is. The more people, the more crowded it gets.
Additional notes:
The grey info boxes point out special things worth knowing, like recurring weather issues or seasonal events.
Nagasaki, located on the island of Kyushu, experiences a humid subtropical climate marked by mild winters and long, hot, humid summers. Average daily temperatures range from about 7°C in January to 28°C in August. Winters are generally mild, with rare snowfall and occasional cold snaps, while summers are hot and oppressive, with high humidity and temperatures frequently reaching 30°C or more. The city’s proximity to the sea moderates temperature extremes, and winter nights rarely drop below freezing.
Rainfall is a defining feature of Nagasaki’s climate, making it one of Japan’s wettest cities. Annual precipitation averages between 1,900 and 2,200 mm, with the heaviest rainfall occurring in June and July during the 'tsuyu' (plum rain) season. Typhoons can bring intense rain and strong winds from August to October. Despite the rain, Nagasaki enjoys around 1,900 hours of sunshine annually, with the sunniest period in late summer and early autumn. Sea temperatures are suitable for swimming from June to October, peaking at 27–28°C in August. Winds are generally moderate but can become strong during typhoons.
| Average climate data for Nagasaki, Japan | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Average maximum temperature (°C) | 10 | 12 | 15 | 20 | 24 | 26 | 30 | 32 | 29 | 24 | 18 | 13 | 32 |
| Average minimum temperature (°C) | 4 | 5 | 7 | 11 | 16 | 20 | 24 | 25 | 22 | 16 | 11 | 6 | 4 |
| Average precipitation (mm) | 64 | 87 | 133 | 150 | 178 | 311 | 316 | 198 | 191 | 86 | 86 | 61 | 1,862 |
| Average rainfall days (days) | 11 | 10 | 12 | 11 | 11 | 14 | 12 | 10 | 10 | 6 | 9 | 10 | 125 |
| Average snowfall (mm) | 20 | 10 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 10 | 40 |
| Average snowfall days (days) | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 3 |
| Average relative humidity (%) | 66 | 64 | 67 | 68 | 72 | 79 | 80 | 76 | 73 | 68 | 66 | 65 | 70 |
| Average water temperature (°C) | 17 | 15 | 15 | 16 | 19 | 22 | 26 | 28 | 27 | 24 | 22 | 18 | 21 |
| Average daily daylight hours (h) | 10 | 11 | 12 | 13 | 13 | 14 | 14 | 13 | 12 | 11 | 10 | 10 | 12 |
| Average daily sunshine hours (h) | 3 | 4 | 4 | 5 | 5 | 4 | 5 | 6 | 5 | 5 | 4 | 3 | 4 |
| Average UV index | 3 | 5 | 7 | 9 | 10 | 10 | 11 | 11 | 9 | 6 | 4 | 3 | 7 |
The best time to visit Nagasaki is during spring (mid-April to mid-May) and autumn (mid-October to mid-November). These periods offer mild, comfortable temperatures, lower humidity, and less rainfall, making them ideal for sightseeing, enjoying cherry blossoms or autumn foliage, and outdoor activities.
The least favourable time for travel is from June to early September, when Nagasaki experiences its rainy season and peak typhoon activity. Heavy rainfall, high humidity, and the risk of typhoons can disrupt travel plans and outdoor activities, making sightseeing less enjoyable.
Nagasaki has a humid subtropical climate with mild winters and hot, humid summers. Rainfall is abundant, especially in June and July, and the city experiences four distinct seasons.
The rainy season, known as 'tsuyu,' occurs from early June to mid-July. This period brings heavy, frequent rainfall and high humidity to the city.
Snowfall in Nagasaki is rare and usually light. Winters are generally mild, with temperatures rarely dropping below freezing, though occasional cold snaps can occur.
Summer temperatures in Nagasaki typically range from 24°C at night to 32°C during the day. High humidity can make it feel even hotter, especially in July and August.
Yes, Nagasaki can be affected by typhoons from August to October. Typhoons bring intense rain and strong winds, so travellers should check weather updates during this period.
The sea around Nagasaki is suitable for swimming from June to October, with water temperatures peaking at 27–28°C in August. Winters are too cool for comfortable swimming.
Cherry blossoms in Nagasaki typically reach their peak around late March to early April, offering beautiful scenery and pleasant weather for outdoor activities.
The warmest month, with the highest average maximum temperature, is August (31.6 °C). The month with the lowest average maximum temperature is January (10.4 °C). Overall, the average maximum temperature over the whole year is 21 °C.
The month with the highest average minimum temperature is August (25.1 °C). The coldest month, with the lowest average minimum temperature, is January (3.9 °C). Overall, the average minimum temperature over the whole year is 13.9 °C.
The month with the highest average water temperature is August (27.7 °C). The month with the lowest average water temperature is February (15.2 °C). Overall, the average water temperature over the whole year is 20.8 °C.
The wettest month, with the highest amount of precipitation, is July (316 mm). The driest month, with the least amount of precipitation, is December (61.4 mm). Over the whole year there are 1,861.6 mm of rainfall on average.
The month with the most days of rain is June (13.5 days). The month with the fewest days of rain is October (6.1 days). Over the whole year there are 124.6 days of rain on average.
The month with the most snowfall is January (20.1 mm). The months with the least snowfall are March, April, May, June, July, August, September, October and November (0 mm). Over the whole year there are 40 mm of snowfall on average.
The month with the most days of snowfall is January (1.2 days). The months with the fewest days of snowfall are April, May, June, July and September (0 days). Over the whole year there are 2.6 days of snowfall on average.
The month with the highest average relative humidity is July (80.4 %). The month with the lowest average relative humidity is February (64.1 %). The overall average relative humidity over the whole year is 70.3 %.
The month with the longest days, so the most daylight, is June (Average daylight: 14 h). The month with the shortest days, so the least daylight, is December (Average daylight: 10 h). Over the whole year there are 11.9 h of daylight per day on average.
The month with the most sunshine per day is August (Average sunshine: 6.1 h). The month with the least sunshine per day is December (Average sunshine: 3.1 h). Over the whole year there are 4.5 h of sunlight per day on average.
The months with the highest average UV index are July and August (UV index: 11). The months with the lowest average UV index are January and December (UV index: 3). Over the whole year the average UV index is 7.3.
