Planning for the weather is an important factor for making your trip to San Agustinillo a success, especially when you're splurging. The hottest months are usually April and March, with an average temperature of 26°C, while the coldest months are January and February, with an average of 25°C. The rainiest months in San Agustinillo are September, June, August and October, with each month seeing an average of 505 mm of rainfall.