Climate of Nagano Prefecture, Japan
Area-weighted average across Nagano Prefecture. For where people actually live and travel, see the cities below.
Nagano Prefecture, a subdivision of Japan, has a seasonal climate on average. Area-weighted monthly temperatures across the whole territory range from -3.6°C / 25.5°F in January to 21.1°C / 70°F in August, with rainfall from 49 mm / 1.9 in to 220 mm / 8.7 in depending on the season (1554 mm / 61.2 in total across the year). See the city listed below for point-value climate at specific locations — these often differ from the area-weighted average, especially in geographically diverse subdivisions.
| Month | Temperature | Rainfall | Matches |
|---|---|---|---|
| January | -3.6°C25.5°F | 55 mm2.2″ | Snowy |
| February | -3.1°C26.4°F | 64 mm2.5″ | Snowy |
| March | 0.4°C32.7°F | 96 mm3.8″ | Snowy |
| April | 7.1°C44.8°F | 123 mm4.8″ | — |
| May | 12.2°C54°F | 135 mm5.3″ | — |
| June | 16.1°C61°F | 205 mm8.1″ | — |
| July | 20°C68°F | 207 mm8.1″ | — |
| August | 21.1°C70°F | 194 mm7.6″ | — |
| September | 16.8°C62.2°F | 220 mm8.7″ | — |
| October | 10.5°C50.9°F | 129 mm5.1″ | — |
| November | 5°C41°F | 77 mm3″ | — |
| December | -0.4°C31.3°F | 49 mm1.9″ | Snowy |
Frequently asked questions
What is the best time to visit Nagano Prefecture?
Nagano Prefecture, Japan does not have a clear sunny-and-dry window by our cutoffs. The warmest month is August at 21.1°C / 70°F, and the driest is December at 49 mm / 1.9 in — likely your best travel window. For city-level detail, see the cities section below.
What is the climate of Nagano Prefecture?
Nagano Prefecture, Japan has area-weighted monthly average temperatures ranging from -3.6°C / 25.5°F in January to 21.1°C / 70°F in August. Annual rainfall averages about 1554 mm / 61.2 in, with the wettest month being September (220 mm / 8.7 in) and the driest December (49 mm / 1.9 in). Because this is an area average across the whole subdivision, local city values can differ substantially.
What is the hottest month in Nagano Prefecture?
The hottest month in Nagano Prefecture is August, with an area-wide average temperature of 21.1°C / 70°F.
What is the coldest month in Nagano Prefecture?
The coldest month in Nagano Prefecture is January, with an area-wide average temperature of -3.6°C / 25.5°F.
When does it rain most in Nagano Prefecture?
The wettest month in Nagano Prefecture is September, averaging about 220 mm / 8.7 in of rainfall. The driest is December with about 49 mm / 1.9 in.