When you travel with your pet, keeping tabs on the weather can help you make the trip more safe and fun for everyone. 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 Santa María Huatulco are September, June, August and October, with each month seeing an average of 505 mm of rainfall.