If you're looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Koror: The hottest months are usually May and June, with an average temperature of 28°C, while the coldest months are February and March, with an average of 28°C. The rainiest months in Koror are July, June, May and August, with each month seeing an average of 398 mm of rainfall.