Iwaki has a warm temperate climate with warm summers and cold winters.
Temperatures peak in August and drop to their lowest in February, while rainfall is highest during autumn months.
Humidity remains high throughout the year, especially in autumn, creating cold and damp conditions.
| Month | 🌤️ | High | Low | Avg | Humid % | Rain (mm) | Wind (m/s) | Solar (kWh/m²) |
|---|---|---|---|---|---|---|---|---|
| January | 🌨️ | 9.6°C | -6.9°C | 1.3°C | 84% | 52 | 0.9 | 2.22 |
| February | 🌨️ | 12.0°C | -7.4°C | 2.3°C | 82% | 51 | 1.0 | 2.99 |
| March | ☔ | 17.0°C | -5.2°C | 5.9°C | 80% | 95 | 0.9 | 3.89 |
| April | ☔ | 22.9°C | -2.4°C | 10.3°C | 79% | 111 | 0.7 | 4.76 |
| May | ☔ | 26.6°C | 3.3°C | 15.0°C | 80% | 128 | 0.5 | 5.06 |
| June | 🌧️ | 29.8°C | 9.2°C | 19.5°C | 84% | 150 | 0.4 | 4.75 |
| July | 🌧️ | 33.3°C | 14.5°C | 23.9°C | 85% | 170 | 0.3 | 4.44 |
| August | 🌧️ | 33.7°C | 16.2°C | 24.9°C | 84% | 153 | 0.3 | 4.59 |
| September | 🌧️ | 30.7°C | 10.4°C | 20.5°C | 86% | 181 | 0.4 | 3.59 |
| October | ☔ | 25.0°C | 3.3°C | 14.1°C | 86% | 149 | 0.5 | 2.99 |
| November | 🌨️ | 19.4°C | -2.0°C | 8.7°C | 86% | 75 | 0.6 | 2.36 |
| December | 🌨️ | 14.2°C | -4.6°C | 4.8°C | 85% | 52 | 0.7 | 1.97 |
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
Monthly averages · 1981–2025
💧 Humidity peaks at 86% in September · annual avg 83%
The warmest year in Iwaki's recorded history was 2024 (avg: 14.6°C), while the coldest was 1984 (avg: 11.2°C).
Average annual high/low · Last 10 years · °C
Total annual precipitation · Last 10 years · mm/year
| Year | Min Temp | Avg Temp | Max Temp | Rainfall (mm) | Avg Humidity | Avg Wind |
|---|---|---|---|---|---|---|
2025 | 3.2°C | 13.9°C | 24.5°C | 1581 | 84% | 0.6 m/s |
2024 🔥 | 4.3°C | 14.6°C | 25.0°C | 1600 | 84% | 0.7 m/s |
2023 | 3.6°C | 14.1°C | 24.6°C | 1633 | 83% | 0.6 m/s |
2022 | 2.5°C | 12.8°C | 23.2°C | 1260 | 85% | 0.6 m/s |
2021 | 3.1°C | 13.2°C | 23.2°C | 1668 | 84% | 0.7 m/s |
2020 | 3.6°C | 13.0°C | 22.5°C | 1399 | 85% | 0.6 m/s |
2019 | 2.7°C | 13.2°C | 23.8°C | 1543 | 83% | 0.6 m/s |
2018 | 2.4°C | 13.3°C | 24.1°C | 1263 | 83% | 0.6 m/s |
2017 | 2.4°C | 12.6°C | 22.8°C | 1324 | 84% | 0.6 m/s |
2016 | 1.9°C | 12.7°C | 23.6°C | 1371 | 84% | 0.6 m/s |
Showing 1 to 10 of 45 years
Based on 45 years of data (1981–2025), August is typically the hottest month in Iwaki, Fukushima, with average high temperatures around 33.7°C.
February is the coldest month in Iwaki, with average low temperatures around -7.4°C.
September receives the most rainfall with approximately 181 mm, while February is the driest with 51 mm.
The highest recorded temperature was 39.0°C in July 2011. This is part of the historical record spanning 1981–2025.
The lowest recorded temperature was -12.4°C in March 1984.
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.
Iwaki receives the most sunlight in May with an average solar radiation of 5.06 kWh/m²/day. This solar radiation data, sourced from NASA POWER, is useful for solar energy planning and agriculture in Fukushima.
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.
