Weather will likely play an important role when you plan your trip to Arsha, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually August and July with an average temp of 40°F, while the coldest months are January and February with an average of 9°F. The rainiest months in Arsha are June, July, May, and August, with each month seeing an average of 10 inches of rainfall.