Because there are a lot more of these days than snow days. Also, while there are more of these days than snow days, there are actually not THAT many San Diego-type days here. Most of our springs are a mixture of cool and rainy and/or huge jumps in temperature before you can adjust. If it was a string of beautiful, 70 degree days, that would be different. But we will inevitably get a jump from rain and 60 to hot and humid and mid 80's.