Oyama has a warm temperate climate with warm summers and cold winters.
Temperatures peak in August and drop to their lowest in January, while rainfall is highest during autumn months.
Humidity remains high throughout the year, especially in autumn, creating cold and damp conditions.
| Month | 🌤️ | Avg High | Avg Temp | Avg Low | Record High | Record Low | Humid % | Rain (mm) | Wind (m/s) | Solar (kWh/m²) |
|---|---|---|---|---|---|---|---|---|---|---|
| January | 🌨️ | 6.6°C | 2.0°C | -2.6°C | 17.6°C | -8.6°C | 77% | 42 | 1.3 | 2.63 |
| February | 🌨️ | 7.7°C | 2.6°C | -2.5°C | 22.3°C | -9.5°C | 75% | 47 | 1.5 | 3.37 |
| March | ☔ | 12.0°C | 6.0°C | -0.0°C | 24.0°C | -6.1°C | 75% | 95 | 1.6 | 4.16 |
| April | ☔ | 18.1°C | 11.6°C | 5.2°C | 28.4°C | -4.3°C | 76% | 117 | 1.6 | 4.88 |
| May | ☔ | 22.9°C | 16.8°C | 10.8°C | 33.1°C | -0.2°C | 77% | 139 | 1.4 | 5.04 |
| June | 🌧️ | 26.0°C | 20.9°C | 15.8°C | 37.8°C | 6.8°C | 81% | 168 | 1.2 | 4.55 |
| July | 🌧️ | 29.8°C | 25.0°C | 20.2°C | 38.9°C | 10.3°C | 82% | 177 | 1.2 | 4.52 |
| August | 🌧️ | 30.9°C | 26.2°C | 21.5°C | 38.1°C | 13.5°C | 82% | 174 | 1.2 | 4.66 |
| September | 🌧️ | 26.8°C | 22.2°C | 17.6°C | 37.4°C | 6.7°C | 84% | 203 | 1.2 | 3.64 |
| October | 🌧️ | 20.9°C | 15.8°C | 10.8°C | 31.9°C | 0.7°C | 83% | 158 | 1.2 | 3.11 |
| November | 🌨️ | 15.2°C | 9.9°C | 4.5°C | 26.7°C | -3.5°C | 81% | 72 | 1.1 | 2.64 |
| December | 🌨️ | 9.6°C | 4.6°C | -0.5°C | 22.1°C | -6.0°C | 78% | 43 | 1.2 | 2.36 |
Showing average climate conditions across 45 years (1981–2025)
🧥 Expect frosty nights and below-freezing temperatures during this Cold Winter period.
🌤️ Early mornings and evenings are most comfortable during this Hot Summer season.
☔ Heavy Rainfall expected — carry rain gear and plan outdoor activities around these months.
Monthly averages · 1981–2025 climate normals · °C
Temperatures rise steadily from spring, peak in August, and gradually decline through autumn into winter.
These seasonal patterns make summer pleasant for travel, while winters can bring frost and occasional snowfall.
Monthly rainfall · 1981–2025 seasonal trends · mm/month
Rainfall is concentrated in the autumn months. Humidity stays high (around 79%), peaking in autumn, which creates cold and damp conditions.
☔ Heavy Rainfall expected — carry rain gear and plan outdoor activities around these months.
Monthly averages · 1981–2025
Across 45 years of records, Oyama's temperature shows a slight warming trend over the past decade. Its hottest day reached 38.9°C in July 1987, and its coldest dropped to -9.5°C in February 1990. 2024 was the warmest year overall and 1993 the coolest.
The warmest year in Oyama's recorded history was 2024 (avg: 15.4°C), while the coldest was 1993 (avg: 12.5°C).
Average annual high/low · Last 30 years · °C
Total annual precipitation · Last 30 years · mm/year
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall (mm) | Avg Humidity | Avg Wind |
|---|---|---|---|---|---|---|---|---|
2025 | 20.1°C | 14.9°C | 9.7°C | 36.6°C | -5.2°C | 1636 | 80% | 1.3 m/s |
2024 🔥 | 20.5°C | 15.4°C | 10.3°C | 36.6°C | -4.8°C | 1748 | 80% | 1.3 m/s |
2023 | 20.5°C | 15.3°C | 10.0°C | 38.1°C | -6.1°C | 1735 | 79% | 1.3 m/s |
2022 | 19.2°C | 14.1°C | 9.0°C | 37.8°C | -4.9°C | 1371 | 80% | 1.3 m/s |
2021 | 19.3°C | 14.1°C | 8.9°C | 34.9°C | -5.1°C | 1758 | 80% | 1.3 m/s |
2020 | 19.4°C | 14.3°C | 9.2°C | 36.6°C | -4.9°C | 1457 | 81% | 1.3 m/s |
2019 | 19.5°C | 14.2°C | 8.9°C | 37.3°C | -5.5°C | 1610 | 79% | 1.3 m/s |
2018 | 19.9°C | 14.5°C | 9.2°C | 37.3°C | -6.7°C | 1341 | 79% | 1.3 m/s |
2017 | 18.6°C | 13.4°C | 8.1°C | 34.9°C | -4.8°C | 1321 | 79% | 1.3 m/s |
2016 | 19.4°C | 14.1°C | 8.8°C | 34.9°C | -4.9°C | 1521 | 80% | 1.3 m/s |
Showing 1 to 10 of 45 years
Based on 45 years of data (1981–2025), August is typically the hottest month in Oyama, Tochigi, with average high temperatures around 30.9°C.
January is the coldest month in Oyama, with average low temperatures around -2.6°C.
September receives the most rainfall with approximately 203 mm, while January is the driest with 42 mm.
The highest recorded temperature was 38.9°C in July 1987. This is part of the historical record spanning 1981–2025.
The lowest recorded temperature was -9.5°C in February 1990.
This page covers 45 years of climate data from 1981 to 2025. As new data is added to the database the page automatically reflects the updated coverage.
Oyama receives the most sunlight in May with an average solar radiation of 5.04 kWh/m²/day. This solar radiation data, sourced from NASA POWER, is useful for solar energy planning and agriculture in Tochigi.
All climate data is sourced from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite and model data. It provides monthly averages for temperature, precipitation, humidity, wind speed, and solar radiation.
All weather data is sourced from NASA POWER (Prediction of Worldwide Energy Resources), a NASA project providing solar and meteorological data for renewable energy, building efficiency, and agricultural research.
