The Sims 3 Seasons Cheats, Codes & Guides
Before You Cheat
Get your snuggie! Winter is coming
Change The Seasons
If you are tired of any season that you are in, you can press Ctrl+Shift+C and then type in "testingcheatsenabled true". After you've done that, you go to your sim's house and you shift+click on your sim's foundation (aka the ground I guess) and one of the options should say "Seasons..." or something like that. You can change the temperature, you can change the weather, and you can change the season. It's very helpful.
Control Weather and Wind without the Climatron Control Unit
Ctrl+Shift+C "testingcheatsenabled true"
If you don't already have "testingcheatsenabled true" then bring up the cheat window by pressing Ctrl+Shift+C, Enter testingcheatsenabled true
Then hover your cursor over the ground on any lot any where hold Left Shift+ Left mouse Click a interaction will show "Seasons" from there you can control the weather season and wind.
In addition to this cheat you can get the "Time/Weather Change Mod" from the MOD the Sims can change time/Cloud cover and more.