Weather can make or break a roadtrip, so we've gathered some data about year-round temperatures in Monywa to help you plan yours. The hottest months are usually April and May with an average temp of 89°F, while the coldest months are January and December with an average of 74°F. The rainiest months in Monywa are September, August, October, and July, with each month seeing an average of 8 inches of rainfall.