Nagano climate
Nagano (Japan) has a hot-summer humid continental climate (Köppen Dfa). The average temperature over the year is 12 °C54 °F, and about 1,462 mm58 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Nagano climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin |
|---|---|---|---|---|
| Jan | 337 | −622 | −130 | 953.8 |
| Feb | 540 | −523 | 032 | 692.7 |
| Mar | 948 | −130 | 439 | 903.5 |
| Apr | 1762 | 440 | 1051 | 893.5 |
| May | 2373 | 1151 | 1762 | 1003.9 |
| Jun | 2679 | 1661 | 2170 | 1405.5 |
| Jul | 3086 | 2169 | 2577 | 1997.8 |
| Aug | 3087 | 2170 | 2679 | 1556.1 |
| Sep | 2679 | 1762 | 2171 | 1706.7 |
| Oct | 2068 | 1050 | 1559 | 1556.1 |
| Nov | 1356 | 338 | 847 | 963.8 |
| Dec | 643 | −229 | 236 | 1044.1 |
| Year | 3087 | −622 | 1254 | 1,46258 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 90% | 63% | 2.3 | 9:55 |
| Feb | 87% | 64% | 3.1 | 10:48 |
| Mar | 82% | 65% | 4.0 | 11:52 |
| Apr | 76% | 64% | 4.9 | 13:05 |
| May | 74% | 68% | 5.4 | 14:06 |
| Jun | 78% | 81% | 4.9 | 14:39 |
| Jul | 81% | 81% | 4.6 | 14:26 |
| Aug | 81% | 72% | 4.8 | 13:33 |
| Sep | 83% | 75% | 3.8 | 12:22 |
| Oct | 84% | 70% | 3.1 | 11:11 |
| Nov | 86% | 60% | 2.5 | 10:09 |
| Dec | 88% | 60% | 2.1 | 9:40 |
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 Nagano is like
The warmest month is August, with an average high of 30 °C87 °F and a low of 21 °C70 °F. The coldest is January, when highs average 3 °C37 °F and lows −6 °C22 °F. Seasons are strongly marked: the warmest month is on average 27.1 °C48.8 °F warmer than the coldest.
It is wet, with about 1,462 mm58 in of precipitation per year. The wettest three-month stretch is July–September, which brings 36% of the annual total. The wettest month is July (199 mm7.8 in), the driest is February (69 mm2.7 in).
Relative humidity ranges from 74% in May to 90% in January. The clearest skies (lowest average cloud amount, 60%) are typical of December. Average wind speed near the ground ranges from 4 km/h (3 mph) in August to 9 km/h (6 mph) in March. Daylight lasts from about 9.7 hours in December to 14.7 hours in June.
Best time to visit Nagano
Based on these averages, the most comfortable months for sightseeing and outdoor activities are May. Average highs then reach 23 °C73 °F to 23 °C73 °F. Precipitation is 100 mm3.9 in to 100 mm3.9 in per month.
The most challenging month is January, which is cold, with average highs of 3 °C37 °F.
Comfort score: months are ranked by how close they come to an ideal. That means 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 Nagano
- Winter (December–February) — highs 337 to 6 °C43 °F, lows −622 to −2 °C29 °F, about 89 mm3.5 in of precipitation a month. Pack a warm coat, layers and closed shoes and shoes with good grip, as frost is common.
- Spring (March–May) — highs 948 to 23 °C73 °F, lows −130 to 11 °C51 °F, about 93 mm3.7 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket, an extra layer for the cooler mornings and evenings and an umbrella or light rain jacket.
- Summer (June–August) — highs 2679 to 30 °C87 °F, lows 1661 to 21 °C70 °F, about 165 mm6.5 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and an umbrella or light rain jacket.
- Autumn (September–November) — highs 1356 to 26 °C79 °F, lows 338 to 17 °C62 °F, about 140 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 Nagano compares
The nearest larger place is Takasaki, about 82 km to the southeast. Compared with it, Nagano is on average 1.7 °C3.1 °F cooler. It receives a similar amount of precipitation. The difference is largest in January (2.4 °C4.3 °F cooler).
World Climates covers 111 places in Japan. By annual mean temperature, Nagano is the 87th warmest of them. By annual precipitation, it is the 87th wettest. See all of them on the Japan climate page.
Some places in other countries have a very similar pattern of temperature and rainfall. The closest matches are Philadelphia (United States, Dfa), Staten Island (United States, Dfa) and Baltimore (United States, Dfa).
The same NASA POWER grid cell also contains Ueda (pop. 157,480). Their long-term averages in this dataset are essentially the same as for Nagano, so they do not have separate pages.
Nearby places
- Climate in Matsumoto 50 km · 12 °C54 °F · 1,329 mm52 in
- Climate in Jōetsu 56 km · 15 °C58 °F · 1,812 mm71 in
- Climate in Takasaki 82 km · 14 °C58 °F · 1,434 mm56 in
- Climate in Maebashi 85 km · 14 °C57 °F · 1,469 mm58 in
- Climate in Toyama 86 km · 15 °C59 °F · 1,810 mm71 in
- Climate in Takaoka 105 km · 15 °C59 °F · 2,104 mm83 in
- Climate in Nagaoka 107 km · 14 °C57 °F · 1,922 mm76 in
- Climate in Kofu 115 km · 14 °C58 °F · 1,598 mm63 in
Frequently asked questions
What is the warmest month in Nagano?
August is the warmest month in Nagano. Its average high is 30 °C (87 °F) and its average low is 21 °C (70 °F).
What is the coldest month in Nagano?
January is the coldest month. Its average high is 3 °C (37 °F) and its average low is -6 °C (22 °F).
When does it rain the most in Nagano?
July is the wettest month with about 199 mm (7.8 in) of precipitation. February is the driest with about 69 mm (2.7 in).
What is the best time to visit Nagano?
Judging by long-term averages, the most comfortable months are May.
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. The gaps are largest 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 875 m, while Nagano lies at about 372 m. Temperatures on this page were therefore adjusted by +3.3 °C5.9 °F using the standard lapse rate of 6.5 °C per 1,000 m.