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 Captiva: The hottest months are usually August and July, with an average temperature of 28°C, while the coldest months are January and February, with an average of 20°C. The rainiest months in Captiva are August, June, September and July, with each month seeing an average of 178 mm of rainfall.