Climate and monthly weather forecastNagasaki, Japan
Climate and monthly weather forecast
The climate of Nagasaki
Nagasaki, situated in the northwestern region of Kyushu Island in Japan, is characterized by a humid subtropical climate, as per the Köppen climate classification (designated as Cfa). The climate exudes a fundamental quality of tepidity throughout the year, marked by hot, humid summers and mild, chilly winters. An outstanding characteristic of Nagasaki's weather is its high level of precipitation and high relative humidity.Throughout the range of twelve months, a varied spectrum of temperatures and weather conditions can be observed in Nagasaki. The city tends to realize the warmest temperatures from July to September, with an average high ranging from 30.1°C (86.2°F) in July to 28.6°C (83.5°F) in September. Conversely, the coldest temperature tends to be witnessed between December and February, with the average low extending from 5.9°C (42.6°F) in December to 3.8°C (38.8°F) in February. In terms of rainfall, the highest volume is registered from June to July, realizing an average precipitation level from 315mm (12.4") in June to 314mm (12.36") in July.
The level of relative humidity in Nagasaki is rather high all year round, with slight fluctuations. The highest average humidity, around 80%, tends to be noticed between June and July, while the lowest average humidity, about 64%, is experienced during February. Remarkably, snowfall is also a component of the city's weather but considerably infrequent and primarily limited to January and December, with snowfall measures at 20mm (0.79") and 10mm (0.39") respectively.
The best time to visit Nagasaki
The ideal time to travel to Nagasaki would be in the spring period from April to June. During these months, temperatures are reasonably moderate with April highs about 19.7°C (67.5°F) and dropping to lows around 11.6°C (52.9°F). The rainfall tends to be relatively light with approximately 151mm (5.94") falling in April. Besides, the weather conditions encapsulate comfortable humidity levels and appreciable daylight, which contribute to a hospitable environment for outdoor activities.The worst time to visit Nagasaki
Traveling to Nagasaki might be quite challenging during the summer months of June and July, classified by torrential rainfall. During these months, the city experiences heavy downpours with rainfall levels reaching a colossal 315mm (12.4") in June and 314mm (12.36") in July. Notably, these conditions can disrupt outdoor sightseeing plans and create unwelcome travel disruptions.Spring weather in Nagasaki
The spring season in Nagasaki, stretching from March to May, marks a transition from winter's cold to summer's warmth. The period witnesses mellow warm temperatures, with average highs ranging from 14.8°C (58.6°F) in March to 23.5°C (74.3°F) in May, and lows varying from 7.3°C (45.1°F) to 15.8°C (60.4°F). An uptick in rainfall can be detected with levels progressively increasing from 132mm (5.2") in March to 179mm (7.05") in May, signifying the imminent arrival of the rain-drenched summer season.Summer weather in Nagasaki
The summer months in Nagasaki, from June to August, are characterized by extreme heat and copious rainfall. The average temperatures rise steeply with highs oscillating from 26.4°C (79.5°F) in June to 31.7°C (89.1°F) in August while the lows remain warm, recorded from 20°C (68°F) to 25.1°C (77.2°F). Notably, June and July experience the harshest rainy conditions, drawing in more than 300mm (11.81") of precipitation.Autumn weather in Nagasaki
Autumn, extending from September to November, revels in mild weather with a steady reduction in temperature and rainfall in Nagasaki. During this period, average high temperatures gradually decrease from 28.6°C (83.5°F) in September to 18.3°C (64.9°F) in November. Simultaneously, the average low temperatures have a downward tilt too, dipping from 21.8°C (71.2°F) in September to 10.8°C (51.4°F) in November. The rainfall amount sees a drastic reduction as it almost halves from 189mm (7.44") in September to 86mm (3.39") in November.Winter weather in Nagasaki
The winter season in Nagasaki, covering December to February, is marked by cooler temperatures and reduced rainfall. The average high temperature during this season ranges from 13.1°C (55.6°F) in December to 10.4°C (50.7°F) in February, while the average low is clocked at 5.9°C (42.6°F) in December dropping to 3.8°C (38.8°F) in February. Despite these chilly conditions, the city enjoys a generally snow-free winter - except for the light snowfall recorded in January and December.Weather in January
January in Nagasaki, Japan ushers in the new year with an average high temperature of 10.4°C (50.7°F) and a low temperature of 3.8°C (38.8°F). This month is significantly colder compared to the temperatures experienced in December of the previous year. Weather in January »Weather in February
February sees a slight increase in temperatures from 10.4°C (50.7°F) to 11.7°C (53.1°F) in the high range, and from 3.8°C (38.8°F) to 4.4°C (39.9°F) in the low. Relative humidity rises slightly compared to January, creating a sense of dampness in the air. Weather in February »Weather in March
A noticeable change in weather sets in during the month of March in Nagasaki, Japan. The city experiences an average high of 14.8°C (58.6°F) and a low of 7.3°C (45.1°F). The area also records its third highest rainfall for the year, averaging 132mm (5.2") for the month. Weather in March »Weather in April
The city of Nagasaki fully embraces spring in April, with the temperatures soaring from a high of 14.8°C (58.6°F) in March to 19.7°C (67.5°F), and the lows moving up from 7.3°C (45.1°F) to 11.6°C (52.9°F). The jump in temperatures is accompanied by the highest recorded level of rainfall, with an average of 151mm (5.94"). Weather in April »Weather in May
In May, Nagasaki, Japan sees a marked increase in average temperatures, from 19.7°C (67.5°F) to 23.5°C (74.3°F) on the higher end, and 11.6°C (52.9°F) to 15.8°C (60.4°F) on the lower spectrum. The city experiences its second highest rainfall for the year, averaging 179mm (7.05") for the month. Weather in May »Weather in June
June in Nagasaki introduces the summer season in full swing, with average high temperatures registering at 26.4°C (79.5°F) and lows at 20°C (68°F). A significant pattern emerges in June, which records the highest rainfall of 315mm (12.4"), signaling the onset of the monsoon cycle. Weather in June »Weather in July
Nagasaki swelters in July with the thermometer spiking to an average high of 30.1°C (86.2°F) and a low of 24.3°C (75.7°F). The city records the same amount of rainfall as it did in June, with 314mm (12.36"). This is indicative of the summer monsoon season in full effect, bringing bouts of heavy rain. Weather in July »Weather in August
In Nagasaki, Japan, August suffers the highest average high temperature of 31.7°C (89.1°F) and a low of 25.1°C (77.2°F). Despite the heat, it is a popular month for beachgoers, especially with the sea temperature at a year-high average of 27.7°C (81.9°F). Weather in August »Weather in September
September brings the first signs of fall to Nagasaki with a decline in temperature from 31.7°C (89.1°F) to 28.6°C (83.5°F) in the higher range, and from 25.1°C (77.2°F) to 21.8°C (71.2°F) on the low end. A slight decrease in rainfall to 189mm (7.44") signals the definitive end of the monsoon season. Weather in September »Weather in October
October in Nagasaki sees a significant dip in temperature both in daytime highs, which average 23.8°C (74.8°F), and lows, registering at 16.1°C (61°F). The rainfall struggles in the city dwindle to 86mm (3.39"), marking a sharp decline from previous months. Weather in October »Weather in November
November brings further cooling to Nagasaki with the average high and low temperatures dropping to 18.3°C (64.9°F) and 10.8°C (51.4°F) respectively. The average rainfall stands at 86mm (3.39"), nearly identical to the previous month. Weather in November »Weather in December
Finally, the year in Nagasaki comes full circle with December introducing the winter environment, dipping the average high and low temperatures to 13.1°C (55.6°F) and 5.9°C (42.6°F) respectively. After a long period of no snowfall from April to November, snow again becomes a possibility in December with an average of 10mm (0.39"). Weather in December »Updated: Jan 31, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Temperature records in Nagasaki mark January as the coldest month, with highs averaging 10.4°C (50.7°F) and lows at 3.8°C (38.8°F).
In Nagasaki, Japan, during the entire year, the rain falls for 124.7 days and collects up to 1858mm (73.15") of precipitation.
January, February and December are months with snowfall in Nagasaki, Japan.
The month with the most snowfall in Nagasaki is January, when snow falls for 1.2 days and typically aggregates up to 20mm (0.79") of snow.
Throughout the year, in Nagasaki, Japan, there are 2.5 snowfall days, and 40mm (1.57") of snow is accumulated.
January has the least sunshine of the year, with an average of 3.3h of sunshine.
The months with the lowest UV index are January and December, with an average maximum UV index of 3.
With an average relative humidity of 64%, February is the least humid month in Nagasaki.
February and March, with an average sea temperature of 15.3°C (59.5°F), are months with the coldest seawater.
March through November are months without snowfall in Nagasaki, Japan.
The month with the most rainfall in Nagasaki, Japan, is June, when the rain falls for 13.5 days and typically aggregates up to 315mm (12.4") of precipitation.
June has the longest days of the year in Nagasaki, Japan, with an average of 14h and 18min of daylight.
July is the most humid month in Nagasaki, Japan, with an average relative humidity of 80%.
July and August, with an average maximum UV index of 11, are months with the highest UV index in Nagasaki, Japan.
Nagasaki's warmest weather arrives in August, when temperatures average a high of 31.7°C (89.1°F) and a low of 25.1°C (77.2°F).
With an average sea temperature of 27.7°C (81.9°F), August is the month with the warmest seawater in Nagasaki, Japan.
August has the most sunshine of the year, with an average of 6.8h of sunshine.
The month with the least rainfall is December, when the rain falls for 10 days and typically collects 61mm (2.4") of precipitation.
The month with the shortest days is December, with an average of 10h and 0min of daylight.
Nagasaki does not observe Daylight Saving Time (DST). JST timezone is used throughout the entire year.
Average temperature
Nagasaki, Japan
The warmest month (with the highest average high temperature) is August (31.7°C).
The month with the lowest average high temperature is January (10.4°C).
The month with the highest average low temperature is August (25.1°C).
The coldest month (with the lowest average low temperature) is January (3.8°C).
Average humidity
Nagasaki, Japan
The month with the highest relative humidity is July (80%).
The month with the lowest relative humidity is February (64%).
Average rainfall
Nagasaki, Japan
- Average rainfall in January:
64mm - Average rainfall in February:
85.7mm - Average rainfall in March:
132mm - Average rainfall in April:
151.3mm - Average rainfall in May:
179.3mm - Average rainfall in June:
314.6mm
- Average rainfall in July:
314.4mm - Average rainfall in August:
195.4mm - Average rainfall in September:
188.8mm - Average rainfall in October:
85.8mm - Average rainfall in November:
85.6mm - Average rainfall in December:
60.8mm
The wettest month (with the highest rainfall) is June (314.6mm).
The driest month (with the least rainfall) is December (60.8mm).
Average rainfall days
Nagasaki, Japan
- Average rainfall days in January:
11.1 days - Average rainfall days in February:
9.9 days - Average rainfall days in March:
12.5 days - Average rainfall days in April:
10.8 days - Average rainfall days in May:
10.6 days - Average rainfall days in June:
13.5 days
- Average rainfall days in July:
11.6 days - Average rainfall days in August:
9.8 days - Average rainfall days in September:
9.7 days - Average rainfall days in October:
6.2 days - Average rainfall days in November:
9 days - Average rainfall days in December:
10 days
The month with the highest number of rainy days is June (13.5 days).
The month with the least rainy days is October (6.2 days).
Average snowfall
Nagasaki, Japan
The month with the highest snowfall is January (20mm).
The months with the least snowfall are March, April, May, June, July, August, September, October and November (0mm).
Average snowfall days
Nagasaki, Japan
- Average snowfall days in January:
1.2 days - Average snowfall days in February:
0.9 days - Average snowfall days in March:
0.2 days - Average snowfall days in April:
0 days - Average snowfall days in May:
0 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0 days - Average snowfall days in November:
0 days - Average snowfall days in December:
0.2 days
The month with the highest number of snowfall days is January (1.2 days).
The months with the least snowfall days are April, May, June, July, August, September, October and November (0 days).
Average sea temperature
Nagasaki, Japan
The best month for swimming (with the highest average sea temperature) is August (27.7°C).
The coldest months (with the lowest average sea temperature) are February and March (15.3°C).
Average daylight / Average sunshine
Nagasaki, Japan
- Average daylight in January:
10h and 18min - Average daylight in February:
11h and 0min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 0min - Average daylight in May:
13h and 48min - Average daylight in June:
14h and 18min
- Average daylight in July:
14h and 6min - Average daylight in August:
13h and 18min - Average daylight in September:
12h and 24min - Average daylight in October:
11h and 24min - Average daylight in November:
10h and 30min - Average daylight in December:
10h and 0min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in January:
3h and 18min - Average sunshine in February:
4h and 18min - Average sunshine in March:
4h and 48min - Average sunshine in April:
5h and 48min - Average sunshine in May:
5h and 54min - Average sunshine in June:
4h and 30min
- Average sunshine in July:
5h and 48min - Average sunshine in August:
6h and 48min - Average sunshine in September:
5h and 48min - Average sunshine in October:
5h and 54min - Average sunshine in November:
4h and 36min - Average sunshine in December:
3h and 48min
The month with the most sunshine is August (Average sunshine: 6h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 18min).
Average UV index
Nagasaki, Japan
The months with the highest UV index are July and August (UV index 11).
The months with the lowest UV index are January and December (UV index 3).
