Climate in Nagano, Japan

Nagano, Japan has a humid subtropical climate. The annual average temperature is about 19°C and the city receives roughly 1500 mm of precipitation across 168 rainy days a year, with around 953 hours of sunshine. The warmest month is Jul (highs near 29.7°C) and the coldest is Jan (lows near 8.3°C). These are deterministic, latitude- and region-based planning estimates — not a forecast or measured station data; check current conditions with an official meteorological service before travel.

Data year 2025; last updated 2026-05-16.

Nagano is classified as Humid Subtropical. This reflects its annual temperature range and the seasonal pattern of its rainfall.

Nagano receives about 1500 mm of precipitation a year over roughly 168 rainy days. The wettest month is Jul and the driest is Jan.

Nagano sees an estimated 953 hours of sunshine a year, concentrated in the warmer months around Jul.

By temperature and rainfall, the most comfortable months in Nagano are Oct, Nov, Apr. Conditions vary year to year — verify with a current forecast before booking.

Nagano has a climate comfort score of 77/100, a very comfortable year-round climate by this measure. The score weights mild temperatures most, then rainfall balance, sunshine, low seasonality, and the absence of extreme winter cold or summer heat.