San Andreas is generally a sunny state. Yeah it can get rainy here and there, but most of the time, you're bathing in the warm sunlight. Not feeling too sunny today? Change up the weather whenever you like!
With the weather cheat, you can scroll through various weather effects like clear, cloudy, and smoggy, by inputting the specific code each time.
Secondly, if the car physics seem a little too precise for you, maybe the Slidey cars are what you're looking for. With this cheat active, you'll be fishtailing and gliding across the street as if you were on ice. Wheeee!
Remember, using these cheats will disable you from gaining Achievements in the game.