Climate Insights for Yamaguchi

The climate in Yamaguchi is temperate. The average annual temperature is 16°C and approximately 1769mm of precipitation falls per year. Yamaguchi receives a notable amount of rainfall throughout the year, including during its driest month. Yamaguchi 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. Light snow can occur between January and December.

Temperatures in Yamaguchi vary considerably across the year, with a 30°C difference between the coldest and warmest months. The warmest month is August, when average highs reach 32°C and the mean temperature sits around 28°C. January is the coolest month, with minimum temperatures around 2°C and an average of 5°C. Daily temperature variation is modest, with an average difference of 8°C between highs and lows. The sharpest temperature change occurs between September and October, with a 6°C shift in average temperatures.

Yamaguchi is a fairly wet location, receiving approximately 1769mm of precipitation annually, which averages out to around 147mm per month. The wettest month is July, averaging 272mm of rainfall. June and September also tend to see above-average precipitation. The driest month is December, with just 64mm. That's 208mm less than July, the wettest month. Precipitation varies noticeably between seasons, with the second half (July to December) of the year generally seeing more rainfall. Light snowfall can occur between January and December, totalling around 10cm annually. January is the snowiest month with approximately 5cm.

Yamaguchi is relatively calm, with an average annual wind speed of 9km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is February, averaging 10km/h, though still comfortable for most outdoor activities. The calmest conditions occur in June, with average winds dropping to 8km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 2km/h between the calmest and windiest months.

It is currently summer in Yamaguchi, which began on June 21, 2026. Yamaguchi 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 32°C, while the coldest stretch bottoms out in January near 2°C. Autumn is next, beginning on September 23, 2026 (3 days from now).

The best time to visit Yamaguchi is during October, when the weather is most comfortable for travellers. During these months, average temperatures hover around 19°C with modest rainfall averaging 91mm per month. By contrast, August can be uncomfortably hot with highs reaching 32°C, while January is the coldest period with lows dropping to 2°C. Despite being the best months overall, some rain is still likely. Pack a waterproof layer and plan a mix of indoor and outdoor activities.

The table below shows monthly climate averages for Yamaguchi 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.