If you're looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Jamnagar: The hottest months are usually May and April, with an average temperature of 30°C, while the coldest months are January and February, with an average of 24°C. The rainiest months in Jamnagar are July, September, August and June, with each month seeing an average of 225 mm of rainfall.