Weather is probably a major factor when you plan your trip to Lihir Island, but bear 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 temperature of 27°C, while the coldest months are August and September, with an average of 27°C. The rainiest months in Lihir Island are March, December, April and January, with each month seeing an average of 418 mm of rainfall.