If you’re hoping to get lost in the rain on your romantic getaway, take a look at these details about year-round temperatures in Whitsunday Island: The hottest months are usually December and January, with an average temperature of 26°C, while the coldest months are July and June, with an average of 19°C. The rainiest months in Whitsunday Island are February, January, March and December, with each month seeing an average of 222 mm of rainfall.