There is a weather system which allows edits to parameters for each specific weather in Skyrim. All weather configurations are placed in a folder named enbseries which, in turn, is placed within the root Skyrim directory.
To use the weather system, users must download the ENB helper mod and install it to the Data folder just like any other normal mod is installed.
If using an ENB preset with custom weathers, then this parameter found under the
[WEATHER] section must be enabled to use the customized weathers.
Reference to use to fill this description in more.