There’s nothing like an all-inclusive holiday in Termas de Rio Hondo to revive you, especially when you know what to expect from the elements. Here’s some information to help you decide when to book: The hottest months are usually January and December, with an average temperature of 26°C, while the coldest months are July and June, with an average of 16°C. August and July are the driest months, while January and February are the rainiest months.