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 May, with an average temperature of 20°C, while the coldest months are January and February, with an average of 17°C. The rainiest months in San Agustin Lanquin are September, June, August and October, with each month seeing an average of 520 mm of rainfall.