The most pleasant months of the year for Jenner are August, July and September. In Jenner, there are 6 comfortable months with high temperatures in the range of 70-85°. August is the hottest month for Jenner with an average high temperature of 77.3°, which ranks it as cooler than most places in California. Any measurable snowfall is a rare occurance in Jenner. There are few days during the summer when the humidity becomes unpleasant.