Weather is probably a major factor when you plan your trip to Sumisip, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually May and April with an average temp of 82°F, while the coldest months are February and January with an average of 80°F. The rainiest months in Sumisip are June, July, August, and September, with each month seeing an average of 13 inches of rainfall.