If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Deema Range: The hottest months are usually May and June with an average temp of 82°F, while the coldest months are January and December with an average of 59°F. The rainiest months in Deema Range are July, August, September, and June, with each month seeing an average of 11 inches of rainfall.