Planning for the weather is a good way to make your trip to Atherton relaxing and enjoyable, especially when you’re splurging. The hottest months are usually December and November, with an average temperature of 24°C, while the coldest months are August and July, with an average of 19°C. The rainiest months in Atherton are January, February, March and December, with each month seeing an average of 229 mm of rainfall.