If you're looking for summer vibes, the best time to travel to San Luis Obispo, CA is in September, October and June, when the average temperature reaches 28.6 °C, while June, October and September are the 3 sunniest months of the year, with an average of 172.67 hours.
However, if you prefer colder temperatures, make sure you visit San Luis Obispo, CA during January, February or December to experience an average of 3.82 °C.
For those who don't care too much about temperatures, but want to avoid getting wet in the rain, it's important to avoid travelling during August, September and January, when the average precipitation in San Luis Obispo, CA is 3.4 mm, while the months of January, February and March are drier, with an average of 0 mm.