If you’re hoping to get lost in the rain on your romantic getaway, take a look at these details about year-round temperatures in Iida: The hottest months are usually August and July, with an average temperature of 21°C, while the coldest months are January and February, with an average of 1°C. The rainiest months in Iida are July, June, September and August, with each month seeing an average of 347 mm of rainfall.