Weather is probably a major factor when you plan your trip to Njombe, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually November and October with an average temp of 77°F, while the coldest months are July and June with an average of 69°F. The rainiest months in Njombe are January, February, March, and December, with each month seeing an average of 12 inches of rainfall.