According to the 2023 USDA Hardiness Zone Map San Clemente, California is in Zones 10a (30°F to 25°F) and 10b (35°F to 30°F). There is no change from the 2012 USDA Hardiness Zone Map which has San Clemente in also in Zones 10a (30°F to 25°F) and 10b (35°F to 30°F).