The hottest month in Stinson Beach is July when the average maximum temperature is 26°, average temperature is 19° and average minimum temperature is 11°.
The coolest month in Stinson Beach is January when the average maximum temperature is 16°, average temperature is 8° and average minimum temperature is 1°.
The longest days in Stinson Beach are in June, with an average of 14.8 hours of daylight per day. December has the shortest days with an average of 9.6 hours of daylight per day.
The sunniest days in Stinson Beach are in June 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 5.1 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 10.6 and lowest in December when it reaches 2.2.
An ultraviolet index reading of 8 to 10 indicates a very high risk of harm from unprotected sun exposure. Unprotected skin risks burning in less than 15 minutes. Take extra precautions because unprotected skin and eyes will be damaged and can burn quickly. 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 Stinson Beach are found in August when they peak at 19° and lowest in May when they dip to 12°.
The sea is best for swimming between June and December when the temperature is above 16° which is cold for swimming, a full wet suit is required to spend any length of time in the sea.
The wettest month in Stinson Beach is December with 12cm of rain and the most days of rain with 8.7 days with some rain, a dry time to visit the beach.
The driest month in Stinson Beach is July with 0cm of rain and the least days of rain with 0.3 days with some rain, an extremely dry time to visit the beach.
The most humid month in Stinson Beach is August with a dew point (an indicator of humidity) of 15° which is comfortable for everyone.
The least humid month in Stinson Beach is January with a dew point of 7° which is a bit dry for some.
The most windy month in Stinson Beach is May when the average maximum windspeed is 25kmh and the average wind speed is 9kmh.
The least windy month in Stinson Beach is December when the average maximum windspeed is 18kmh and the average wind speed is 5kmh.