Climate in Nagaoka, Japan

Nagaoka, Japan has a humid subtropical climate. The annual average temperature is about 18.6°C, with around 952 hours of sunshine; the national rainfall baseline is roughly 1500 mm across 168 rainy days a year. The warmest month is Jul (highs near 29.4°C) and the coldest is Jan (lows near 7.8°C). These are deterministic planning estimates, not a forecast or measured station data. Temperature and sunshine follow the city's latitude; rainfall and the climate zone come from a country-level baseline that every city in the country shares (refined by region in the United States, Canada and Australia), so they do not show local differences. Check current conditions with an official meteorological service before travel.

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

Nagaoka is classified as Humid Subtropical. The classification combines the city’s own temperature range, which follows its latitude, with a rainfall pattern taken at country level for Japan — so cities in the same country usually share a zone.

The rainfall baseline for Japan is about 1500 mm a year over roughly 168 rainy days, with the wettest month Jul and the driest Jan. This figure is not specific to Nagaoka: every city in Japan carries the same baseline, so it will not show the difference between, say, a dry inland city and a wet coastal one. Use an official meteorological service for local rainfall.

Nagaoka sees an estimated 952 hours of sunshine a year, concentrated in the warmer months around Jul.

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

Nagaoka 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.