Planning for the weather is an important factor for making your trip to Santo Tomas a success, especially when you’re splurging. The hottest months are usually May and April, with an average temperature of 28°C, while the coldest months are January and February, with an average of 26°C. The rainiest months in Santo Tomas are July, September, August and June, with each month seeing an average of 466 mm of rainfall.