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 Saku: The hottest months are usually August and July, with an average temperature of 20°C, while the coldest months are January and February, with an average of 0°C. The rainiest months in Saku are July, August, September and June, with each month seeing an average of 266 mm of rainfall.