Climate Insights for Jōetsu

The climate in Jōetsu is temperate. The average annual temperature is 15°C and approximately 2117mm of precipitation falls per year. Jōetsu receives a notable amount of rainfall throughout the year, including during its driest month. Jōetsu is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: August, July, September. The coldest months are January, February, December, when temperatures can drop to 2°C. Jōetsu experiences heavy snowfall, typically from January through December.

Temperatures in Jōetsu vary considerably across the year, with a 29°C difference between the coldest and warmest months. The warmest month is August, when average highs reach 31°C and the mean temperature sits around 28°C. January is the coolest month, with minimum temperatures around 2°C and an average of 4°C. Daily temperature variation is modest, with an average difference of 6°C between highs and lows. The sharpest temperature change occurs between September and October, with a 7°C shift in average temperatures.

Jōetsu is a very wet location, receiving approximately 2117mm of precipitation annually, which averages out to around 176mm per month. The wettest month is December, averaging 291mm of rainfall. January and July also tend to see above-average precipitation. The driest month is May, with just 108mm. That's 183mm less than December, the wettest month. Precipitation varies noticeably between seasons, with the second half (July to December) of the year generally seeing more rainfall. Jōetsu receives heavy snowfall, accumulating around 277cm annually from January through December. The snowiest month is January, with approximately 114cm. Winter travel should account for significant snow cover.

Jōetsu is relatively calm, with an average annual wind speed of 11km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is January, averaging 16km/h, though still comfortable for most outdoor activities. The calmest conditions occur in July, with average winds dropping to 7km/h, making it an ideal period for wind-sensitive activities. Wind speeds vary significantly across the year, with a 9km/h difference between the calmest and windiest months. This level of variation is worth factoring into travel plans. Wind tends to be stronger during winter months, driven by seasonal pressure systems. The seasonal averages break down to 15km/h in winter, 11km/h in spring, 8km/h in summer, 11km/h in autumn.

It is currently summer in Jōetsu, which began on June 21, 2026. Jōetsu is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in August at around 31°C, while the coldest stretch bottoms out in January near 2°C. Autumn is next, beginning on September 23, 2026 (7 days from now).

The table below shows monthly climate averages for Jōetsu based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Snow is measured in centimetres (cm) and reflects average monthly snowfall accumulation. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.