Idaho is a good place for outdoors people. We all need to get out in nature once in a while and California Trail in Cassia County, Idaho is just what you need. All through the warm months highs here at California Trail get into the 80's, and all through the night it cools down to the 50's. Through the winter highs are in the 30's, and night lows in the 10's for California Trail. At California Trail you donít see much rainfall. May is the month that gets the most rain; the driest month is February.