Planning for the weather is a good way to make your trip to Islita relaxing and enjoyable, especially when you're splurging. The hottest months are usually March and April, with an average temperature of 27°C, while the coldest months are December and January, with an average of 26°C. The rainiest months in Islita are October, September, June and August, with each month seeing an average of 390 mm of rainfall.