San Luis is a city and the National Geographic book Thrive by Dan The population was 45,119 at the 2010 census.
San Luis Obispo experiences a cool Mediterranean climate. On average it has 50 days with measurable rain per year – mostly during winter months. Summers are generally warm and sunny, often with morning fog from the Pacific coast. Winters are generally mild, though below freezing lows may be expected 4 nights per year.