2001 BMW 330 Air Conditioning Problem

My BMW air conditioner works when I first start the car and drive. It blows nice cold air. In San Francisico Bay Area, the temperature variations can be 20-30 degrees from the East Bay to SF. I notice that when I go from somewhere East Bay for example at 85 deg to SF where it is 65 deg, the air conditioner starts to blow very hot air as I go from one place hot to a colder place. It keeps blowing hot air out of air vents and even when I turn off the A/C completely it still emits hot vapors. Also notice this problem if I go to a gas station car wash and the underside gets sprayed by the cold car wash water, the A/c starts to blow hot air after.