The hottest month in San Luis Obispo County is August when the average maximum temperature is 29°, average temperature is 20° and average minimum temperature is 13°.
The coolest month in San Luis Obispo County is January when the average maximum temperature is 18°, average temperature is 11° and average minimum temperature is 4°.
The longest days in San Luis Obispo County are in June, with an average of 14.5 hours of daylight per day. December has the shortest days with an average of 9.8 hours of daylight per day.
The sunniest days in San Luis Obispo County are in July which has the most hours of sunshine per day with an average of 11.2 hours of sunshine per day, making it a very sunny and pleasant month with long bright days. December has the least sunshine with an average of 5.9 hours of sunshine per day, making it a sunny month that is overcast at times.
The ultraviolet index is the highest in July when it reaches 11.3 and lowest in December when it reaches 2.8.
An ultraviolet index reading above 11 indicates an extreme risk of harm from unprotected sun exposure. Unprotected skin risks burning in less than 10 minutes. Take all precautions because unprotected skin and eyes can burn in minutes. Tanning will be safest before 10am and after 4pm but only with a good application of sun screen. For those with sensitive skin stay in the shade and wear protective clothing, a wide-brimmed hat, and UV-blocking sunglasses. Generously apply broad spectrum SPF 30+ sunscreen every 2 hours, even on cloudy days. Watch out for relections from water that may increase ultraviolet exposure.
The warmest sea water temperatures in San Luis Obispo County are found in September when they peak at 19° and lowest in April when they dip to 14°.
The sea is best for swimming between May and December when the temperature is above 16° which is cool for swimming, shorty wetsuit may help you extend your time in the water.
The wettest month in San Luis Obispo County is December with 63.9cm of rain and February has the most days of rain with 11.5 days with some rain, a wet time to visit the beach.
The driest month in San Luis Obispo County is July with 0.1cm of rain and the least days of rain with 0.4 days with some rain, an extremely dry time to visit the beach.
The most humid month in San Luis Obispo County is July with a dew point (an indicator of humidity) of 13° which is very comfortable.
The least humid month in San Luis Obispo County is January with a dew point of 7° which is a bit dry for some.
The most windy month in San Luis Obispo County is May when the average maximum windspeed is 32kmh and the average wind speed is 12kmh.
The least windy month in San Luis Obispo County is December when the average maximum windspeed is 23kmh and the average wind speed is 7kmh.
