If you’re looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Vieux Grand Port: The hottest months are usually February and January, with an average temperature of 26°C, while the coldest months are August and July, with an average of 22°C. The rainiest months in Vieux Grand Port are January, February, March and December, with each month seeing an average of 180 mm of rainfall.