Planning for the weather is a good way to make your trip to Jaco relaxing and enjoyable, especially when you’re splurging. The hottest months are usually March and April, with an average temperature of 28°C, while the coldest months are January and December, with an average of 27°C. The rainiest months in Jaco are October, August, July and November, with each month seeing an average of 992 mm of rainfall.