Climate Insights for Ōyama

The climate in Ōyama is temperate. The average annual temperature is 18°C and approximately 2452mm of precipitation falls per year. Ōyama receives a notable amount of rainfall throughout the year, including during its driest month. Ōyama 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 7°C.

Temperatures in Ōyama vary considerably across the year, with a 21°C difference between the coldest and warmest months. The warmest month is August, when average highs reach 28°C and the mean temperature sits around 27°C. January is the coolest month, with minimum temperatures around 7°C and an average of 9°C. Daily temperature variation is modest, with an average difference of 3°C between highs and lows. The sharpest temperature change occurs between November and December, with a 5°C shift in average temperatures.

Ōyama is a very wet location, receiving approximately 2452mm of precipitation annually, which averages out to around 204mm per month. The wettest month is June, averaging 366mm of rainfall. October and July also tend to see above-average precipitation. The driest month is January, with just 84mm. That's 282mm less than June, the wettest month. Precipitation varies noticeably between seasons, with the second half (July to December) of the year generally seeing more rainfall.

Ōyama is relatively calm, with an average annual wind speed of 6km/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 8km/h, though still comfortable for most outdoor activities. The calmest conditions occur in July, with average winds dropping to 5km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 3km/h gap between the calmest and windiest months. Wind tends to be stronger during winter months, driven by seasonal pressure systems. The seasonal averages break down to 7km/h in winter, 5km/h in spring, 5km/h in summer, 6km/h in autumn.

It is currently summer in Ōyama, which began on June 21, 2026. Ōyama 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 28°C, while the coldest stretch bottoms out in January near 7°C. Autumn is next, beginning on September 23, 2026 — 92 days from now.

The table below shows monthly climate averages for Ōyama 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. 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.