Weather in Nagasaki

Planning your visit to Nagasaki? Stay up to date with the latest weather data! Below is the current information and forecasts to help you perfectly plan your time in this amazing city in Japan.

The city of Nagasaki, located in Japan, is characterised by a humid subtropical climate. This means that there are four distinct seasons, each with its own features. Overall, the weather is distinguished by notable temperature fluctuations throughout the year, offering visitors diverse experiences depending on the time of their visit.

Summer in Nagasaki, covering the period from June to August, is warm and humid. Average temperatures during this time rise to 22-28°C, with August being the hottest month. It is during the summer months, especially June and July, that rainfall increases and the highest number of rainy days occurs. Winters, from December to February, are mild and cool here, with average temperatures around 8-10°C. Although the total amount of precipitation in winter is lower, overcast days are not uncommon.

Spring (March-May) and autumn (September-November) in Nagasaki are pleasant transitional seasons. In spring, the temperature gradually rises, and nature comes alive, whilst in autumn, the summer heat gives way to comfortable warmth. These periods are usually characterised by moderate rainfall and a large number of sunny days, making them very attractive for travelling and exploring the city's sights.

The climate in Nagasaki demonstrates noticeable seasonal temperature changes, offering diverse conditions throughout the year. The coldest month is traditionally January, when the average air temperature is around 8.2°C. During this period, average minimum temperatures can drop to 6.5°C, and daily maximums rarely exceed 10.0°C. On the other end of the spectrum is August – the hottest month. The average temperature in August reaches 27.8°C, while the daytime heat can raise the thermometer to 29.5°C, and nights remain very warm, with an average minimum of around 26.1°C.

The summer months in Nagasaki, from June to August, are characterised by consistently high temperatures. In June, the average temperature settles at 22.6°C (minimum 20.9°C, maximum 24.3°C), smoothly transitioning to the hotter figures of July with an average temperature of 26.4°C (minimum 25.1°C, maximum 27.8°C). In summer, the difference between day and night temperatures is relatively small, creating a feeling of constant warmth, which, combined with high humidity, can be perceived as quite muggy weather. For example, in July and August, daily temperature fluctuations (the difference between avg_max and avg_min) are only 2.7-3.4°C.

The winter period, covering December, January, and February, brings a noticeable chill to Nagasaki, although without severe frosts. The average temperature in December is around 9.6°C, dropping to the annual minimum in January, and rising slightly in February to 8.9°C (minimum 6.9°C, maximum 10.9°C). In winter, daily temperature fluctuations are somewhat larger than in summer, reaching 3.5-4.5°C (for example, in March, the difference between 14.5°C and 10.0°C), which implies a more noticeable drop in temperature during the night and morning hours compared to daytime maximums. Nevertheless, winter here remains comparatively mild.

In Nagasaki, there is a pronounced seasonality in the distribution of precipitation throughout the year. The city receives the greatest amount of moisture during the summer months, indicating the presence of a distinct rainy season. Winter and autumn months, conversely, are characterised by a significantly lower volume of precipitation.

The peak of the rainy season in Nagasaki falls in June and July. These months see the highest amount of precipitation, averaging 11 mm each, making them the wettest of the year. July also stands out with the maximum number of rainy days – on average 18 days, meaning it rains for more than half the month. June also sees rain quite frequently, with about 15 rainy days. May (7 mm of precipitation, 13 rainy days) and August (9 mm of precipitation, 14 rainy days) are also quite wet, preceding and continuing the main peak of the season.

The driest period in Nagasaki is late autumn and early winter. The "driest" month in terms of precipitation is considered to be December, when only about 2 mm falls. Low figures are also characteristic of October and November (3 mm each). In terms of the number of rainy days, October is the least rainy – only about 8 days with precipitation. Overall, from October to February, the amount of precipitation and the frequency of rain decrease noticeably compared to the summer period. Given the temperature regime, precipitation predominantly falls as rain.

When packing your suitcase for a trip to Nagasaki, it is important to consider its pronounced seasonality and humid climate. Comfortable shoes for walking are your main companion at any time of the year, as the city is conducive to walking tours. The principle of layering clothes will become your best friend, especially in spring (March-May) and autumn (September-November). During these periods, the weather can be changeable: average temperatures range from 12°C to 25°C, and days can be both sunny and rainy (10-13 rainy days per month). A light jacket or windbreaker, a sweater or fleece that can be easily taken off or put on, will be very useful. Do not forget an umbrella, as precipitation is possible even in relatively dry months.

Summer in Nagasaki (June-August) is a time of heat and high humidity, as well as the peak of the rainy season. June and July are the wettest months with precipitation around 11 mm and 15-18 rainy days. Average temperatures during this period stay at the level of 22-28°C. Therefore, your luggage must include light, breathable clothing made of natural fabrics, a hat for sun protection, and sunscreen. A reliable umbrella or a light raincoat is simply essential to comfortably endure the frequent, though not always prolonged, summer downpours.

In winter (December-February), cool weather settles in Nagasaki with average temperatures around 8-10°C. Although there are no severe frosts, you will need warm clothes: sweaters, a warm jacket (preferably windproof and capable of withstanding light rain, as on average 10-11 days a month may have precipitation, even if the total amount is small – 2-4 mm), a hat, and gloves, especially if you are sensitive to the cold. A small folding umbrella will also not go amiss. Regardless of the season, remember that visiting temples and some traditional establishments in Japan may require removing your shoes, so choose footwear that is easy to take off and put on.