Weather is probably a major factor when you plan your trip to Wewak, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually May and October with an average temp of 80°F, while the coldest months are February and January with an average of 80°F. The rainiest months in Wewak are March, April, December, and November, with each month seeing an average of 15 inches of rainfall.