The most pleasant months of the year for the 91371 zip code are April, May and November. In the 91371 zip code, there are 5 comfortable months with high temperatures in the range of 70-85°. August is the hottest month for the 91371 zip code with an average high temperature of 95.0°, which ranks it as warmer than most places in California. Any measurable snowfall is a rare occurance in the 91371 zip code. There are few days during the summer when the humidity becomes unpleasant.