Weather is probably a major factor when you plan your trip to Jamnagar, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually May and April with an average temp of 86°F, while the coldest months are January and February with an average of 75°F. The rainiest months in Jamnagar are July, September, August, and June, with each month seeing an average of 9 inches of rainfall.