Nagasaki Weather in May

Season: Spring

In short:
1. The perceived temperature of Nagasaki in May is comfortable overall.
2. The ultraviolet rays are strong, so you’d better take proper sun protection measures like applying sunscreen.
3. Precipitation mainly reflects on intermittent slight rainfalls and a few days of heavy rain.

4. Make arrangements in advance if you decide to visit Nagasaki in early May when it is the Golden Week of Japan.

What Is the Temperature Like in May in Nagasaki?

Warmth can be regarded as one of the most prominent features of the Nagasaki weather in May. The average high temperature and low temperature are 24 degrees Celsius (75.2 degrees Fahrenheit) and 16℃ (60.8℉), respectively. Generally, the temperature around noon is 20-24℃ (68-75.2℉), and temperature in the early morning and evening is cooler, at 15-18℃ (59-64.4℉). The lowest temperature seldom goes lower than 12℃ (53.6℉).

The sea temperature is 19℃ (66.2℉) on average in May, which is not suitable for swimming.

Sunny View by the Seaside in Nagasaki

Rainfall & Humidity

There are approximately 16 days of rainy weather on average in May in Nagasaki, with an average monthly precipitation of 190 mm. Heavy rainfalls may occur 3 to 4 times; but broadly speaking, they usually do not last for a whole day. The usual situation is that the rainfall is intermittent, which may cause inconvenience for hanging out, so don’t forget to carry your rain gear.

Monthly average relative humidity of May in Nagasaki is about 73%.

Meganebashi Bridge in Overcast Weather

Wind

Most of the time, the climate of Nagasaki in May is characterized by gentle and moderate breeze. Strong winds may occur occasionally, accompanied by rain showers, especially in the mountainous area. For the sake of safety, if you want to climb the Mount Inasa, you’d better choose a good time when the sky is clear rather than rainy. However, if you choose to take the cableway in a cloudy or slight rainy morning or afternoon, you may enjoy a picturesque view of Nagasaki being shrouded in mist.

Mountains Shrouded in Mist in Nagasaki

Daylight Hours & Sunshine Hours

The sun rises at around 5:22 and sets at around 19:11, and the average daylight during May in Nagasaki is 13 hours per day. Average sunlight in this month is 6 hours every day with an average UV index of 10, which is at a very high level. You are recommended not to be exposed under the sunlight for too long during the period from 10 am to 2 pm.

Wise Dressing for Nagasaki Trip in May

Upper

In early May, you can wear a thin coat with good ventilation characteristics over a long-sleeved shirt. In the middle or later periods of this month, you can directly wear a summer T-shirt or a dress in fine weather; if you start your day early, you can add a long-sleeved shirt and remove it at noon.

Bottom
Thin jeans or thin casual pants are enough for Nagasaki trip in May. Summer shorts or skirts are recommended in late May because by this time, the temperature in the day, especially in sunny days, can approach 27-28℃ (80.6-82.4℉).

Shoes
Canvas sneakers or any ventilated shoes are suitable for you to wear in May in Nagasaki. Sandals are also OK if you feel hot.

Other Necessities
The ultraviolet rays in May are strong, so you need to take proper sun protection measures. For example, apply sunscreen lotions with strong sun protection properties, wear a bucket hat or sunbonnet, and use a parasol to shade from the sun.

Top Reasons for Visiting Nagasaki in May

From a climatic perspective, Nagasaki in May is warm overall and only a little hot but in a friendly way. The perceived temperature is quite comfortable. Although rain is inevitable, it is usually intermittent and mild. In general, your trip will not be affected much by the weather.

In terms of the convenience of travel, you can spare more space in your luggage for other travel items like the camera since clothes you wear in May are both thin and light.

In addition, you can experience diversified landscape and activities in May. In the early month, there are tens of thousands of azalea blossoms with pink and red colors decorating the Mount Inasa. And there is an annual festival, the Azalea Festival, held at the Mount Inasa Park where the karaoke party, kite flying and music events are also included. In late May, colorful hydrangeas are in bloom in places like the Kofukuji Temple and the Meganebashi Bridge.

Shopping at the Local Nagasaki Store

Street View of Nagasaki in Cloudy May

Travel Tips for Nagasaki Trip in May

1. From late April to early May, Japanese will have a few days of holiday off work, forming the “Golden Week” of tourism industry. You can avoid traveling in Nagasaki during this time when it will be crowded with a lot of tourists. If you are just available in early May in 2026 to visit Nagasaki, you are recommended to book your flight ticket and reserve the local hotel in advance because they will rise in price and may run out of stock.

2. If you want to attend the Azalea Festival at the Mount Inasa Park, you are recommended to go there in the afternoon. You can stay there till dusk to overlook the marvelous night view of Nagasaki standing on the top of the Mount Inasa. But remember to bring a coat or a shawl and don’t return too late since the temperature in the mountain is much cooler at night.

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7-Day Nagasaki Weather Forecast