Yamaguchi has a warm temperate climate with warm summers and mild winters.
Yamaguchi has an average annual temperature of 16.1°C across all 16 cities, with approximately 1639 mm of annual precipitation and average humidity of 79%. Temperatures peak in August and drop to their lowest in February, while rainfall is highest during summer months.
The warmest city is Mine with average July highs of 29.7°C, while Mine is the coldest with average January lows of 2.4°C. Humidity remains high throughout the year creating warm and humid conditions. These seasonal patterns offer comfortable conditions year-round, with warm summers and mild winters.
| Month | 🌤️ | Avg High | Avg Temp | Avg Low | Record High | Record Low | Humid % | Rain (mm) | Wind (m/s) | Solar (kWh/m²) |
|---|---|---|---|---|---|---|---|---|---|---|
| January | 🌤️ | 8.6°C | 6.1°C | 3.5°C | 19.9°C | -4.8°C | 76% | 63 | 2.9 | 2.10 |
| February | 🌤️ | 9.4°C | 6.5°C | 3.5°C | 20.2°C | -6.5°C | 75% | 75 | 2.8 | 2.90 |
| March | ⛅ | 12.8°C | 9.4°C | 5.9°C | 23.1°C | -1.9°C | 76% | 121 | 2.5 | 3.80 |
| April | ⛅ | 17.5°C | 13.7°C | 10.0°C | 26.3°C | 0.3°C | 77% | 136 | 2.0 | 4.90 |
| May | 🌧️ | 21.6°C | 17.9°C | 14.2°C | 30.4°C | 5.2°C | 79% | 158 | 1.7 | 5.30 |
| June | 🌧️ | 25.0°C | 21.9°C | 18.7°C | 33.9°C | 10.3°C | 83% | 253 | 1.4 | 4.80 |
| July | 🌧️ | 28.7°C | 25.9°C | 23.0°C | 36.5°C | 14.9°C | 85% | 256 | 1.4 | 5.00 |
| August | 🌧️ | 29.9°C | 27.1°C | 24.3°C | 37.0°C | 17.3°C | 83% | 165 | 1.7 | 5.10 |
| September | 🌧️ | 26.7°C | 23.9°C | 21.0°C | 33.6°C | 9.9°C | 81% | 181 | 2.0 | 4.10 |
| October | ⛅ | 21.6°C | 18.6°C | 15.7°C | 30.2°C | 5.6°C | 78% | 95 | 2.3 | 3.50 |
| November | 🌤️ | 16.4°C | 13.6°C | 10.8°C | 25.3°C | 1.3°C | 76% | 77 | 2.4 | 2.60 |
| December | 🌤️ | 11.1°C | 8.5°C | 5.9°C | 22.6°C | -3.9°C | 76% | 60 | 2.8 | 2.00 |
Showing average climate conditions across 45 years (1981–2025) · averaged across all 16 cities in Yamaguchi
🧥 Light layers are sufficient — this Mild Winter stays cool without prolonged hard freezes.
🌤️ Conditions are ideal for outdoor activities throughout the day in this Mild Summer.
☔ Heavy Rainfall expected — carry rain gear and plan outdoor activities around these months.
Region-wide monthly averages across 16 cities · 1981–2025 · °C
Temperatures rise steadily from spring, peak in August, and gradually decline through autumn into winter.
These seasonal patterns offer comfortable conditions year-round, with warm summers and mild winters.
Region-wide monthly rainfall · 1981–2025 · mm/month
💧 Humidity peaks at 85% in July · annual avg 79%
Monthly averages · 1981–2025
Across 45 years, Yamaguchi's temperature shows a slight warming trend over the past decade. 2024 was the warmest year overall and 1984 the coolest.
The warmest year on record was 2024 (avg: 17.4°C), while the coldest year was 1984 (avg: 15.1°C).
Averaged across all 16 cities in Yamaguchi · Last 30 years · °C
Averaged across all 16 cities in Yamaguchi · Last 30 years · mm/year
🔥 hottest · ❄️ coldest · 🌧️ wettest
ℹ️ Values are averages across all 16 cities in Yamaguchi for each year.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall (mm) | Avg Humidity | Avg Wind |
|---|---|---|---|---|---|---|---|---|
2025 | 19.7°C | 16.8°C | 13.8°C | 37.0°C | -2.7°C | 2016 | 79% | 2.1 m/s |
2024 🔥 | 20.3°C | 17.4°C | 14.5°C | 35.6°C | -2.3°C | 2249 | 81% | 2.1 m/s |
2023 | 20.0°C | 17.0°C | 14.0°C | 34.8°C | -4.1°C | 2033 | 79% | 2.0 m/s |
2022 | 19.6°C | 16.6°C | 13.5°C | 34.6°C | -1.8°C | 1450 | 77% | 2.0 m/s |
2021 | 19.6°C | 16.6°C | 13.6°C | 34.0°C | -3.4°C | 2034 | 79% | 2.1 m/s |
2020 | 19.4°C | 16.4°C | 13.4°C | 34.8°C | -0.7°C | 2065 | 79% | 2.1 m/s |
2019 | 19.7°C | 16.7°C | 13.6°C | 35.0°C | -0.3°C | 1737 | 79% | 2.0 m/s |
2018 | 19.2°C | 16.2°C | 13.2°C | 36.5°C | -2.5°C | 1865 | 79% | 2.1 m/s |
2017 | 19.0°C | 16.0°C | 13.0°C | 34.5°C | -0.8°C | 1660 | 78% | 2.1 m/s |
2016 🌧️ | 19.7°C | 16.7°C | 13.7°C | 34.6°C | -3.8°C | 2305 | 81% | 2.0 m/s |
Showing 1 to 10 of 45 years
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.
