Weather is probably a major factor when you plan your trip to Kasauli, and keep in mind that cheaper options are usually available when the weather isn’t as good. The hottest months are usually June and May with an average temp of 86°F, while the coldest months are January and December with an average of 60°F. The rainiest months in Kasauli are July, August, September, and June, with each month seeing an average of 7 inches of rainfall.