Board Thread:Support Requests - Getting Technical/@comment-5558012-20161127042301/@comment-1757994-20161127053439

There appears to be a variable, which is in frames/second. The default value is 20.

The value looks like it is checked every frame, so you should be able to set it before or after loading the script.

A lower value should be slower snow.

Disclaimer: I haven't actually tested it myself.