Nagasaki climate
Nagasaki (Japan) has a humid subtropical climate (Köppen Cfa). The average temperature over the year is 17 °C62 °F, and about 2,078 mm82 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Nagasaki climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin | Frost days |
|---|---|---|---|---|---|
| Jan | 1049 | 338 | 744 | 712.8 | 3 |
| Feb | 1153 | 439 | 846 | 993.9 | 2 |
| Mar | 1458 | 643 | 1051 | 1315.2 | 0 |
| Apr | 1967 | 1051 | 1559 | 1676.6 | 0 |
| May | 2475 | 1559 | 1967 | 1867.3 | 0 |
| Jun | 2780 | 1967 | 2373 | 33313 | 0 |
| Jul | 3085 | 2474 | 2780 | 35214 | 0 |
| Aug | 3188 | 2476 | 2882 | 2258.9 | 0 |
| Sep | 2882 | 2169 | 2476 | 2017.9 | 0 |
| Oct | 2373 | 1560 | 1966 | 1174.6 | 0 |
| Nov | 1763 | 1051 | 1457 | 1034.1 | 0 |
| Dec | 1253 | 542 | 948 | 923.6 | 0 |
| Year | 3188 | 338 | 1762 | 2,07882 | 6 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total. Frost days are for the whole grid cell.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 79% | 83% | 2.0 | 10:13 |
| Feb | 78% | 76% | 2.9 | 10:58 |
| Mar | 77% | 72% | 3.9 | 11:53 |
| Apr | 78% | 70% | 4.9 | 12:57 |
| May | 80% | 70% | 5.2 | 13:50 |
| Jun | 84% | 80% | 4.5 | 14:18 |
| Jul | 86% | 67% | 5.3 | 14:06 |
| Aug | 83% | 59% | 5.6 | 13:21 |
| Sep | 84% | 62% | 4.5 | 12:19 |
| Oct | 81% | 59% | 3.7 | 11:18 |
| Nov | 80% | 70% | 2.6 | 10:25 |
| Dec | 79% | 81% | 1.9 | 10:00 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Nagasaki is like
The warmest month is August, with an average high of 31 °C88 °F and a low of 24 °C76 °F. The coldest is January, when highs average 10 °C49 °F and lows 3 °C38 °F. Seasons are strongly marked: the warmest month is on average 21.1 °C38 °F warmer than the coldest.
It is very wet, receiving about 2,078 mm82 in of precipitation per year. The wettest three-month stretch is June–August, which brings 44% of the annual total. The wettest month is July (352 mm14 in), the driest is January (71 mm2.8 in).
Relative humidity ranges from 77% in March to 86% in July. The clearest skies (lowest average cloud amount, 59%) are typical of August. Average wind speed near the ground ranges from 4 km/h (2 mph) in June to 7 km/h (4 mph) in January. Daylight lasts from about 10.0 hours in December to 14.3 hours in June.
Best time to visit Nagasaki
Based on these averages, the most comfortable months for sightseeing and outdoor activities are October: average highs of 23 °C73 °F to 23 °C73 °F with 117 mm4.6 in to 117 mm4.6 in of precipitation per month.
The most challenging month is July, which is very wet (352 mm14 in) and humid (86% relative humidity).
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for Nagasaki
- Winter (December–February) — highs 1049 to 12 °C53 °F, lows 338 to 5 °C42 °F, about 87 mm3.4 in of precipitation a month. Pack a warm coat, layers and closed shoes.
- Spring (March–May) — highs 1458 to 24 °C75 °F, lows 643 to 15 °C59 °F, about 162 mm6.4 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket and an umbrella or light rain jacket.
- Summer (June–August) — highs 2780 to 31 °C88 °F, lows 1967 to 24 °C76 °F, about 303 mm12 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and a good rain jacket or umbrella and quick-drying shoes.
- Autumn (September–November) — highs 1763 to 28 °C82 °F, lows 1051 to 21 °C69 °F, about 141 mm5.5 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket and an umbrella or light rain jacket.
How Nagasaki compares
Compared with Kumamoto, about 76 km to the east, Nagasaki has practically the same average temperature and receives a similar amount of precipitation. The difference is largest in December (0.8 °C1.5 °F warmer).
Of the 111 places in Japan covered by World Climates, Nagasaki is the 21st warmest by annual mean temperature and the 13th wettest by annual precipitation. See all of them on the Japan climate page.
Places in other countries with the most similar temperature and rainfall pattern: Ningbo (China, Cfa), Cixi (China, Cfa) and Jeju City (South Korea, Cfa).
Nearby places
- Isahaya 18 km · 16 °C61 °F · 2,078 mm82 in
- Sasebo 49 km · 17 °C62 °F · 2,078 mm82 in
- Ōmuta 62 km · 17 °C62 °F · 2,130 mm84 in
- Saga 66 km · 17 °C62 °F · 2,078 mm82 in
- Honmachi 72 km · 17 °C63 °F · 2,326 mm92 in
- Kumamoto 76 km · 17 °C62 °F · 2,130 mm84 in
- Karatsu 77 km · 17 °C63 °F · 1,963 mm77 in
- Fukuoka 107 km · 16 °C61 °F · 1,901 mm75 in
Frequently asked questions
What is the warmest month in Nagasaki?
August is the warmest month in Nagasaki, with an average high of 31 °C (88 °F) and an average low of 24 °C (76 °F).
What is the coldest month in Nagasaki?
January is the coldest month, with an average high of 10 °C (49 °F) and an average low of 3 °C (38 °F).
When does it rain the most in Nagasaki?
July is the wettest month with about 352 mm (13.9 in) of precipitation; January is the driest with about 71 mm (2.8 in).
What is the best time to visit Nagasaki?
Judging by long-term averages, the most comfortable months are October.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.
The grid cell’s average elevation is 116 m, while Nagasaki lies at about 15 m. Temperatures on this page were therefore adjusted by +0.7 °C1.2 °F using the standard lapse rate of 6.5 °C per 1,000 m.