Planning for the weather is a good way to make your trip to Karnal relaxing and enjoyable, especially when you’re splurging. The hottest months are usually May and June with an average temp of 90°F, while the coldest months are January and December with an average of 63°F. The rainiest months in Karnal are July, August, September, and June, with each month seeing an average of 7 inches of rainfall.