There’s nothing like an all-inclusive vacation in Termas del Arapey to revive you, especially when you know what kind of weather to expect. Here’s some info to help you choose when to book: The hottest months are usually January and February with an average temp of 76°F, while the coldest months are July and June with an average of 56°F. July and June are the driest months while November and October are the rainiest months.