The best time to go to Lake San Marcos for pleasant weather and outdoor activities is generally from late spring to early autumn, specifically from May to October.During these months, you'll experience warm, sunny days with minimal rainfall, which is ideal for enjoying the lake itself and the surrounding attractions. The temperatures are comfortable for golfing, exploring the local trails, or simply relaxing by the water.For those looking to enjoy water sports like kayaking, paddleboarding, or simply swimming, the summer months of July and August offer the warmest lake temperatures. However, this is also peak season, so the area might be busier.If you prefer slightly milder temperatures and fewer crowds, May, June, September, and October are excellent choices.