Weather is probably a major factor when you plan your trip to Irosin, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually May and June with an average temp of 82°F, while the coldest months are February and January with an average of 79°F. The rainiest months in Irosin are December, July, January, and September, with each month seeing an average of 14 inches of rainfall.