Although weather is just one factor, it can really affect your travel plans, especially when you're planning an extended stay in Jinsekikogen. The hottest months are usually August and July, with an average temperature of 25°C, while the coldest months are January and February, with an average of 7°C. The rainiest months in Jinsekikogen are July, June, August and September, with each month seeing an average of 218 mm of rainfall.