Weather is probably a major factor when you plan your trip to Port Douglas, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually February and January with an average temp of 80°F, while the coldest months are August and July with an average of 70°F. The rainiest months in Port Douglas are January, February, March, and December, with each month seeing an average of 11 inches of rainfall.