Nagasaki Weather in August

Season: Summer

In short:
1. August is the hottest month throughout the year in Nagasaki.
2. This month features high humidity and frequent rainfalls especially in the middle and later periods.
3. It is a period with a high incidence of typhoons.
4. There is the night market during the mid and late August on both sides of the Nakashima River. On 15th of August, the Obon Festival is held.

August: Hottest Month of the Year in Nagasaki

The weather of Nagasaki in August is the hottest of the whole year. The average high temperature is 32 degrees Celsius (89.6 degrees Fahrenheit), and the average low temperature is 25℃ (77℉). The minimum temperature is generally at 24-27℃ (75.2-80.6℉), so even in the morning and at night, the perceived temperature is relatively high, not to mention that the temperature during the day is much higher. According to historical statistics, more than two-third days of July had the maximum temperature fluctuating between 30-34℃ (86-93.2℉) and the highest data ever recorded was 37℃ (98.6℉) around noon.

Tourists at the Top of Mount Inasa

Precipitation & Humidity

Nagasaki has an average of 17 rainy days and monthly precipitation of 190 mm in August. Specifically, rainfalls are mainly concentrated in the middle and later periods of the month. In addition, slight and moderate rainfalls are more common, while there are a few days when daily precipitation reaches 30 mm, which, put it in another way, means heavy rain.

The average humidity of August is 80%. The high humidity will make you feel that the perceived temperature is even higher, which may result in sweating and clothes sticking to your skin.

Atomic Bomb Hypocenter on Rainy Day

Daylight Hours & Sunshine Hours

In August, the average duration of daylight is still very long, about 13.4 hours from its beginning at around 5:42 to the end at around 19:05. Daily sunlight duration is much shorter in contrast, about 6 hours, since there are frequent rainy and cloudy days.

The average ultraviolet index of this month is 11, which is at an extremely high level. If sun protection measures are not well taken, your skin is easily to get burnt under the sun.

Wearing Summer Kimono in Nagasaki

Does Typhoon Strike Nagasaki in August?

There is a great possibility that the typhoon will strike Nagasaki in August for 3-5 times, accompanied by heavy rainfall or storm. If it is the case, transportation such as the airplanes, trains, buses and ferries will be suspended or delayed. Therefore, if you plan to travel in Nagasaki in August of 2026, you must pay close attention to the local weather forecast to avoid going there during typhoon days.

Special Events in Nagasaki in August: Night Markets & Obon Festival

The bad weather is unfriendly for visiting Nagasaki in August, but there are actually some surprising things as well. Every year on the weekend of the middle and late August, there is a bustling night market decorated by about 200 lanterns along both banks of the Nakashima River in Nagasaki. You can enjoy delicious food along the streets, and walk around the Meganebashi Bridge, admiring the lively music and dance performances.

Crowded Night Market of Nagasaki

Obon Festival is the most special event in August, held on the 15th. As a tradition, people make exquisite boats which carry the “souls” of the deceased, and transport them through the city as a symbol of sending the deceased souls to the celestial paradise. At this holy night, you will be immersed in a strong cultural atmosphere.

What to Pack for Nagasaki Trip in August?

Clothes

Clothes such as summer T-shirts, shorts, and skirts that you wear are better to be cotton or linen-made, for these fabrics are both light and breathable. Besides, you may keep sweating when hanging out in such a hot month, so make sure these clothes, including the underwear and underpants, are enough for timely change based on your length of stay.

Shoes
Comfortable walking shoes that are well-ventilated are the best choice considering that you spend most of the time wandering in the tourist attractions. Remember to bring several pairs of summer thin socks for your further comfort.

Others

Rain gears like the umbrella or raincoat need to be packed in your suitcase. In addition, sun-protective clothing, sunbonnet and sun glasses are necessary to bring, which can provide physical sun protection. Moreover, the sunscreen cream or lotion is essential to be prepared along your journey in consideration of the strong UV index. Plus, bring a portable bottle so as to keep you hydrated in the hot weather.

Suggestions & Tips for Nagasaki Trip in August

Increasing Tourists in Train Station

With long hours of daylight but hot weather, you are recommended to start your tour early before the temperature rises to an uncomfortable level around noon. If the weather turns too hot or rainy, you can continue your trip in indoor places like the Nagasaki Bomb Museum or the Nagasaki Museum of History & Culture.

Mount Inasa is a great place for escaping the heat as well as a particular spot for appreciating the night view of the Nagasaki city. If you plan to climb it at dusk, you’d better bring a long-sleeved coat because at night, it is much cooler on the top of the mountain than the foot.

Be aware that August is the month of summer holiday in Japan, so the number of tourists will increase accordingly. Therefore, you are recommended to reserve the flight ticket or tickets for tourist attractions before you visit Nagasaki. As for the hotel, it’s better to reserve one in advance that is close to the transportation hub where you can enjoy more convenience.

Nagasaki Weather by Month

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7-Day Nagasaki Weather Forecast