local rainEnt = Entities.CreateByClassname("func_precipitation");
rainEnt.KeyValueFromInt("precipitationtype", 0); 

rainEnt.KeyValueFromVector("mins", Vector(-12000, -12000, -4000));
rainEnt.KeyValueFromVector("maxs", Vector(12000, 12000, 5000));
rainEnt.SetSize(Vector(-12000, -12000, -4000), Vector(12000, 12000, 5000));
rainEnt.SetAbsOrigin(Vector(0, 0, 0));

EntFireByHandle(rainEnt, "Enable", "", 0, null, null);

local fogCtrl = Entities.FindByClassname(null, "env_fog_controller");
if (fogCtrl == null) {
    fogCtrl = Entities.CreateByClassname("env_fog_controller");
}

fogCtrl.KeyValueFromInt("fogenable", 1);
fogCtrl.KeyValueFromString("fogcolor", "100 110 120"); 
fogCtrl.KeyValueFromFloat("fogstart", 200.0);
fogCtrl.KeyValueFromFloat("fogend", 3000.0); // Sichtweite
fogCtrl.KeyValueFromFloat("fogmaxdensity", 0.7); // 70% Dichte

EntFireByHandle(fogCtrl, "TurnOn", "", 0, null, null);