Overview: Kagoshima Kagoshima (Japan) in general has a hot climate. Temperatures during the day are in the range from 12 °C (54 °F) in January to 31 °C (88 °F) in August. The least rainy month in Kagoshima is December with its 9 days of rain, the rainiest month is June, when it rains 18 days. The highest night temperatures could be experienced in August with 24 °C (76 °F), the lowest in January with 4 °C (38 °F).