Weather will likely play an important role when you plan your trip to Saint Martin's Island, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually April and May, with an average temperature of 28°C, while the coldest months are January and February, with an average of 24°C. The rainiest months in Saint Martin's Island are July, June, August and September, with each month seeing an average of 814 mm of rainfall.