Weather is probably a major factor when you plan your trip to Jamui, but bear 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 temperature of 31°C, while the coldest months are January and December, with an average of 20°C. The rainiest months in Jamui are July, August, September and June, with each month seeing an average of 263 mm of rainfall.