Update 2.0 is out for the Piva Weather Mod made for American Truck Simulator.
This mod simulates the spring water by making changes to the vegetation, daylight hours and temperatures.
This mod will change default weather with something more of a greyish skies and more foggy.
Update 0.1.2 is out for the SGate Weather Mod for ATS.
And here is the first version of the Frosty mod made by Grimes.