Weather is probably a major factor when you plan your trip to Chengalpattu, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually May and June with an average temp of 88°F, while the coldest months are January and February with an average of 77°F. The rainiest months in Chengalpattu are November, October, December, and August, with each month seeing an average of 8 inches of rainfall.