Weather will likely play an important role when you plan your trip to Nanyuki, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually March and February with an average temp of 48°F, while the coldest months are January and February with an average of 47°F. The rainiest months in Nanyuki are April, October, November, and December, with each month seeing an average of 15 inches of rainfall.