Sim City 4 Easter Egg - Christmas Snow

step 1: Wait until Christmas time comes around (in your game) OR set system clock to 12/25
step 2: open sim city 4
step 3: load any city
result: when the season date in the game reaches the winter snow will start to gather in areas of high elevation.

I found this egg accidentaly (playing on christmas) it's entertaining but it is also easy to realize why it didn't become a full feature in the game.