If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Coonoor: The hottest months are usually April and March with an average temp of 71°F, while the coldest months are January and February with an average of 66°F. The rainiest months in Coonoor are October, July, August, and May, with each month seeing an average of 10 inches of rainfall.