[Scripting Question] Weather Variety

I have an idea for scripting multiple weather on the same map, but I have no idea how to implement it. I was thinking the pseudo-code would be something like this:

Generate Random number X between 1 and 100
If X <= 5, the weather is rainy
Else, if X <= 15 AND it is daytime, the weather is sunny
Else, no weather

Would something like this work? Has someone already done this? How would I implement such a script and where would it go (sorry, I have very, very little programming experience)?

Basically the easiest way to set this up is a common events and an event on each map to call the common event.
For example I have it change the weather daily so I have an event that checks if I've run a switch that effects the other events and a random number variable that picks a number between 0 and 5 and the conditional branches.
0-Clear Skies
1-Rain
2-Hail
3-Thunder
4-Clear Skies(Unless in Desert then Sand storm)
5-Clear Skies

You could also set up for the weather to be different in areas and use a variable to say what town your in inside the weather event on the map
0-Everywhere Else
1-This town
2-That town

An example, I have a town that rains all the time so I have
0-Clear Skies
1-Rain
2-Rain
3-Thunder
4-Thunder
5-Hail