Planning for the weather is a good way to make your trip to Coonoor relaxing and enjoyable, especially when you're splurging. The hottest months are usually April and March, with an average temperature of 22°C, while the coldest months are January and February, with an average of 19°C. The rainiest months in Coonoor are October, July, August and May, with each month seeing an average of 255 mm of rainfall.