Planning for the weather is a good way to make your trip to Nanyuki relaxing and enjoyable, especially when you’re splurging. 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.