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 Isla Palma: The hottest months are usually February and March, with an average temperature of 28°C, while the coldest months are November and December, with an average of 27°C. The rainiest months in Isla Palma are October, August, September and June, with each month seeing an average of 257 mm of rainfall.