Weatheo

Koriyama Weather by Month

Average temperatures, rainfall and humidity for Koriyama, Japan, month by month, built from OpenWeather’s historical records. Use it to see what a typical Koriyama month looks like before you travel — then check the live Koriyama forecast for the days ahead.

Warmest month

August

30°C average high

Coolest month

January

-3°C average low

Wettest month

September

132 mm of rain

Driest month

January

15 mm of rain

Average temperature and rainfall in Koriyama by month

Averages of the daily highs and lows recorded in each month, with total rainfall, mean humidity and mean wind speed.

MonthAvg highAvg lowRecord low / highRainfallHumidityWind
January6°C-3°C-16°C / 17°C
15 mm
75%12 km/h
February6°C-3°C-15°C / 18°C
29 mm
72%13 km/h
March11°C1°C-9°C / 22°C
66 mm
72%13 km/h
April17°C6°C-8°C / 29°C
104 mm
70%12 km/h
May22°C11°C0°C / 33°C
95 mm
72%11 km/h
June25°C16°C4°C / 39°C
116 mm
81%8 km/h
July29°C20°C13°C / 51°C
126 mm
85%8 km/h
August30°C21°C10°C / 50°C
127 mm
85%8 km/h
September25°C17°C5°C / 36°C
132 mm
85%8 km/h
October19°C10°C-2°C / 30°C
98 mm
81%9 km/h
November14°C4°C-10°C / 25°C
47 mm
79%10 km/h
December8°C-1°C-10°C / 19°C
31 mm
77%11 km/h

Best time to visit Koriyama

The most comfortable time to visit Koriyama is generally May to June and September, balancing mild daytime temperatures against the driest stretch of the year. The city has strongly marked seasons and rain concentrates around September, totalling about 986 mm a year.

Travellers who prefer heat should aim for August, when highs average 30°C. September is the month to avoid if rain would spoil your plans — it averages 132 mm, roughly 9× the rainfall of the driest month (January).

Source: OpenWeather historical and statistical weather data. Values are long-term averages, not a forecast — see the Koriyama forecast for what is happening now.

Weather across Japan right now