Here is a PDF that allows for generating weather patterns for Anwyn.
A year in Anwyn is 12 months long, and each month is 30 days, divided into weeks that are 7 days in length
THe weather tables have adjustments by region of Anwyn (although it contains some older region names which have since changed), and by month of the year.
In determining the weather, the first step is to know the time of year. This will determine modifiers to the base Temperature roll (keep track of this roll). This is the daytime temperature for Anwyn. You subtract 2 from your total to determine the night time temperature. Once you have these, you then modify by region.
Next up, roll for Cloud Cover. Again, this is a single roll, which is then modified by region. If the result is Cloudy or Overcast, you can then roll for Precipitation. If the result is Clear, roll 1d10, divide by 2 (rounding up), and this will be your Wind Factor if there is no Precipitation.
Precipitation is rolled separately for each region and the results will also give you the Wind Factor (the number in parenthsis), so that you can roll for Wind Direction and speed. You can even roll to determine what time of day the precipitation will start. As with temperatures, the time of day is in descriptive elements, not specific times.
Using this system, you only have to roll for Temperature once per month. You would then roll on the Daily Shift table and use the result to determine the shifts on the Temperature table. And then roll the other elements of weather based on Temperature each day.
