I couldn't find the script, So I rewrote it. This script hasn't really been tested, for one thing, it's very hard to test something like this since the weather changes from day to day anyway.
Begin SeasonWeatherScript****************************************************************************;A script to bring simple seasonal weather to Morrowind. ***********************************************************************************************************************************************************************************;ModWeather ;RegionID = Region to change the weather in ;Clear = Chance of clear weather (percent, 0 to 100, float) ;Cloudy = Chance of cloudy weather (percent, 0 to 100, float) ;Foggy = Chance of fog (percent, 0 to 100, float) ;Overcast = Chance of overcast weather (percent, 0 to 100, float) ;Rain = Chance of rain (percent, 0 to 100, float) ;Thunder = Chance of thunder storms (percent, 0 to 100, float) ;Ash = Chance of ash storms (percent, 0 to 100, float) ;Blight = Chance of blight storms (percent, 0 to 100, float) ;Snow = Chance of snow (percent, 0 to 100, float) (Bloodmoon) ;Blizzard = Chance of blizzard (percent, 0 to 100, float) (Bloodmoon)************************************************************************************************** ;ModRegion, "Red Mountain Region", 50, 50, 0, 0, 0, 0, 0, 0, 0, 0;12,1,2 = Winter 3,4,5, = Spring 6,7,8 = Summer 9,10,11 = Fall;1 Sun's Dawn (31 days) Jan;2 First Seed (28 days) Feb;3 Rain's Hand (31 days) Mar;4 Second Seed (30 days) Apr Default weather;5 Mid Year (31 days) May;6 Sun's Height (30 days) Jun;7 Last Seed (31 days) Jul;8 Heartfire (31 days) Aug;9 Frost Fall (30 days) Sep Default Weather;10 Sun's Dusk (31 days) Oct;11 Evening Star (30 days) Nov;12 Morning Star (31 days) Dec short SeasonMonth;Globals: Day MonthIf (MenuMode == 1 ) ReturnendIfIf (SeasonMonth == Month ) ReturnendIfIf ( Month == 1 ) ModRegion, "Ascadian Isles Region" 10, 10, 5, 10, 42, 15, 5, 0, 3, 0 ModRegion, "Ashlands Region" 1, 5, 0, 30, 5, 5, 50, 0, 4, 0 ModRegion, "Azura's Coast Region" 5, 15, 20, 27, 25, 5, 0, 0, 3, 0 ModRegion, "Bitter Coast Region" 4, 5, 5, 20, 60, 5, 0, 0, 1, 0 ModRegion, "Brodir Grove Region" 5, 5, 20, 30, 0, 0, 0, 0, 35, 5 ModRegion, "Felsaad Coast Region" 2, 3, 5, 25, 0, 0, 0, 0, 45, 20 ModRegion, "Grazelands Region" 5, 10, 5, 18, 52, 5, 0, 0, 4, 1 ModRegion, "Hirstaang Forest Region" 5, 10, 10, 30, 0, 0, 0, 0, 30, 15 ModRegion, "Isinfier Plains Region" 1, 3, 0, 26, 0, 0, 0, 0, 45, 25 ModRegion, "Moesring Mountains Region" 2, 3, 0, 20, 0, 0, 0, 0, 30, 45 ModRegion, "Molag Mar Region" 1, 0, 25, 35, 5, 0, 34, 0, 0, 0 ModRegion, "Mournhold Region" 5, 23, 10, 25, 30, 5, 0, 0, 2, 0 ;ModRegion, "Red Mountain Region" 0, 0, 0, 0, 0, 0, 0, 100, 0, 0 ModRegion, "Sheogorad" 1, 9, 5, 20, 20, 10, 0, 0, 25, 10 ModRegion, "Thirsk Region" 5, 5, 10, 30, 0, 0, 0, 0, 35, 15 ModRegion, "West Gash Region" 5, 5, 10, 35, 35, 5, 0, 0, 5, 0 Set SeasonMonth to MonthElseIf ( Month == 2 ) ModRegion, "Ascadian Isles Region" 20, 29, 5, 10, 25, 5, 5, 0, 1, 0 ModRegion, "Ashlands Region" 5, 10, 15, 24, 5, 0, 40, 0, 1, 0 ModRegion, "Azura's Coast Region" 20, 35, 10, 10, 20, 5, 0, 0, 0, 0 ModRegion, "Bitter Coast Region" 5, 10, 15, 20, 40, 10, 0, 0, 0, 0 ModRegion, "Brodir Grove Region" 5, 10, 25, 30, 0, 0, 0, 0, 27, 3 ModRegion, "Felsaad Coast Region" 10, 8, 20, 22, 0, 0, 0, 0, 25, 15 ModRegion, "Grazelands Region" 10, 20, 10, 18, 27, 10, 0, 0, 4, 1 ModRegion, "Hirstaang Forest Region" 10, 20, 10, 30, 8, 0, 0, 0, 15, 7 ModRegion, "Isinfier Plains Region" 5, 5, 0, 30, 0, 0, 0, 0, 38, 22 ModRegion, "Moesring Mountains Region" 5, 5, 0, 20, 0, 0, 0, 0, 27, 43 ModRegion, "Molag Mar Region" 4, 0, 36, 33, 2, 0, 25, 0, 0, 0 ModRegion, "Mournhold Region" 10, 24, 10, 25, 25, 5, 0, 0, 1, 0 ;ModRegion, "Red Mountain Region" 0, 0, 0, 0, 0, 0, 0, 100, 0, 0 ModRegion, "Sheogorad" 5, 20, 5, 20, 20, 10, 0, 0, 15, 5 ModRegion, "Thirsk Region" 10, 8, 20, 22, 0, 0, 0, 0, 25, 15 ModRegion, "West Gash Region" 5, 15, 15, 25, 25, 10, 0, 0, 5, 0 Set SeasonMonth to MonthElseIf ( Month == 3 ) ModRegion, "Ascadian Isles Region" 40, 45, 0, 0, 5, 5, 5, 0, 0, 0 ModRegion, "Ashlands Region" 5, 20, 15, 30, 0, 0, 30, 0, 0, 0 ModRegion, "Azura's Coast Region" 20, 35, 10, 10, 20, 5, 0, 0, 0, 0 ModRegion, "Bitter Coast Region" 10, 45, 10, 0, 25, 10, 0, 0, 0, 0 ModRegion, "Brodir Grove Region" 15, 20, 25, 20, 8, 0, 0, 0, 10, 2 ModRegion, "Felsaad Coast Region" 25, 11, 17, 15, 0, 0, 0, 0, 20, 12 ModRegion, "Grazelands Region" 20, 35, 7, 8, 19, 10, 0, 0, 1, 0 ModRegion, "Hirstaang Forest Region" 20, 35, 5, 25, 8, 0, 0, 0, 5, 2 ModRegion, "Isinfier Plains Region" 8, 8, 0, 30, 0, 0, 0, 0, 34, 20 ModRegion, "Moesring Mountains Region" 8, 8, 0, 22, 0, 0, 0, 0, 22, 40 ModRegion, "Molag Mar Region" 4, 5, 36, 30, 0, 0, 25, 0, 0, 0 ModRegion, "Mournhold Region" 20, 35, 7, 20, 13, 5, 0, 0, 0, 0 ;ModRegion, "Red Mountain Region" 0, 0, 0, 0, 0, 0, 0, 100, 0, 0 ModRegion, "Sheogorad" 10, 25, 15, 20, 15, 10, 0, 0, 4, 1 ModRegion, "Thirsk Region" 25, 11, 17, 15, 0, 0, 0, 0, 20, 12 ModRegion, "West Gash Region" 10, 25, 15, 20, 17, 12, 0, 0, 1, 0 Set SeasonMonth to MonthElseIf ( Month == 4 ) ModRegion, "Ascadian Isles Region" 45, 45, 0, 0, 5, 5, 0, 0, 0, 0 ModRegion, "Ashlands Region" 10, 25, 10, 25, 0, 0, 30, 0, 0, 0 ModRegion, "Azura's Coast Region" 25, 45, 10, 10, 5, 5, 0, 0, 0, 0 ModRegion, "Bitter Coast Region" 10, 60, 10, 0, 10, 10, 0, 0, 0, 0 ModRegion, "Brodir Grove Region" 20, 25, 35, 20, 0, 0, 0, 0, 0, 0 ModRegion, "Felsaad Coast Region" 30, 10, 15, 15, 0, 0, 0, 0, 20, 10 ModRegion, "Grazelands Region" 30, 40, 5, 5, 10, 10, 0, 0, 0, 0 ModRegion, "Hirstaang Forest Region" 20, 40, 0, 40, 0, 0, 0, 0, 0, 0 ModRegion, "Isinfier Plains Region" 10, 10, 0, 30, 0, 0, 0, 0, 30, 20 ModRegion, "Moesring Mountains Region" 10, 10, 0, 20, 0, 0, 0, 0, 20, 40 ModRegion, "Molag Mar Region" 5, 15, 35, 25, 0, 0, 20, 0, 0, 0 ModRegion, "Mournhold Region" 25, 35, 5, 20, 10, 5, 0, 0, 0, 0 ;ModRegion, "Red Mountain Region" 0, 0, 0, 0, 0, 0, 0, 100, 0, 0 ModRegion, "Sheogorad" 15, 40, 10, 15, 10, 10, 0, 0, 0, 0 ModRegion, "Thirsk Region" 20, 25, 25, 20, 0, 5, 5, 0, 0, 0 ModRegion, "West Gash Region" 15, 30, 15, 20, 10, 10, 0, 0, 0, 0 Set SeasonMonth to MonthElseIf ( Month == 5 ) ModRegion, "Ascadian Isles Region" 45, 45, 0, 0, 5, 5, 0, 0, 0, 0 ModRegion, "Ashlands Region" 15, 20, 15, 25, 0, 0, 25, 0, 0, 0 ModRegion, "Azura's Coast Region" 40, 35, 5, 10, 5, 5, 0, 0, 0, 0 ModRegion, "Bitter Coast Region" 20, 40, 5, 20, 10, 5, 0, 0, 0, 0 ModRegion, "Brodir Grove Region" 25, 30, 25, 20, 0, 0, 0, 0, 0, 0 ModRegion, "Felsaad Coast Region" 35, 15, 15, 15, 0, 0, 0, 0, 15, 5 ModRegion, "Grazelands Region" 35, 45, 5, 5, 5, 5, 0, 0, 0, 0 ModRegion, "Hirstaang Forest Region" 30, 40, 0, 30, 0, 0, 0, 0, 0, 0 ModRegion, "Isinfier Plains Region" 20, 20, 0, 25, 0, 0, 0, 0, 20, 15 ModRegion, "Moesring Mountains Region" 15, 10, 0, 30, 0, 0, 0, 0, 20, 25 ModRegion, "Molag Mar Region" 10, 15, 35, 25, 0, 0, 15, 0, 0, 0 ModRegion, "Mournhold Region" 30, 35, 5, 15, 10, 5, 0, 0, 0, 0 ;ModRegion, "Red Mountain Region" 0, 0, 0, 0, 0, 0, 0, 100, 0, 0 ModRegion, "Sheogorad" 25, 45, 5, 15, 5, 5, 0, 0, 0, 0 ModRegion, "Thirsk Region" 35, 15, 20, 15, 0, 0, 0, 0, 10, 5 ModRegion, "West Gash Region" 25, 35, 10, 20, 5, 5, 0, 0, 0, 0 Set SeasonMonth to MonthElseIf ( Month == 6 ) ModRegion, "Ascadian Isles Region" 50, 45, 0, 0, 0, 5, 0, 0, 0, 0 ModRegion, "Ashlands Region" 30, 35, 10, 15, 0, 0, 10, 0, 0, 0 ModRegion, "Azura's Coast Region" 45, 40, 5, 5, 0, 5, 0, 0, 0, 0 ModRegion, "Bitter Coast Region" 30, 40, 5, 10, 10, 5, 0, 0, 0, 0 ModRegion, "Brodir Grove Region" 35, 40, 10, 15, 0, 0, 0, 0, 0, 0 ModRegion, "Felsaad Coast Region" 35, 13, 15, 20, 5, 0, 0, 0, 10, 2 ModRegion, "Grazelands Region" 45, 45, 0, 5, 0, 5, 0, 0, 0, 0 ModRegion, "Hirstaang Forest Region" 40, 40, 0, 20, 0, 0, 0, 0, 0, 0 ModRegion, "Isinfier Plains Region" 25, 25, 0, 25, 0, 0, 0, 0, 15, 10 ModRegion, "Moesring Mountains Region" 20, 15, 0, 30, 0, 0, 0, 0, 15, 20 ModRegion, "Molag Mar Region" 25, 20, 25, 20, 0, 0, 10, 0, 0, 0 ModRegion, "Mournhold Region" 40, 35, 0, 15, 5, 5, 0, 0, 0, 0 ;ModRegion, "Red Mountain Region" 0, 0, 0, 0, 0, 0, 0, 100, 0, 0 ModRegion, "Sheogorad" 35, 30, 0, 25, 5, 5, 0, 0, 0, 0 ModRegion, "Thirsk Region" 35, 18, 15, 20, 5, 0, 0, 0, 5, 2 ModRegion, "West Gash Region" 35, 35, 10, 10, 5, 5, 0, 0, 0, 0 Set SeasonMonth to MonthElseIf ( Month == 7 ) ModRegion, "Ascadian Isles Region" 70, 20, 0, 0, 0, 10, 0, 0, 0, 0 ModRegion, "Ashlands Region" 50, 30, 0, 15, 0, 0, 5, 0, 0, 0 ModRegion, "Azura's Coast Region" 55, 35, 0, 5, 0, 5, 0, 0, 0, 0 ModRegion, "Bitter Coast Region" 50, 35, 0, 5, 5, 5, 0, 0, 0, 0 ModRegion, "Brodir Grove Region" 45, 40, 9, 5, 0, 0, 0, 0, 1, 0 ModRegion, "Felsaad Coast Region" 40, 20, 10, 20, 5, 0, 0, 0, 5, 0 ModRegion, "Grazelands Region" 50, 45, 0, 0, 0, 5, 0, 0, 0, 0 ModRegion, "Hirstaang Forest Region" 45, 45, 0, 10, 0, 0, 0, 0, 0, 0 ModRegion, "Isinfier Plains Region" 35, 25, 0, 25, 0, 0, 0, 0, 10, 5 ModRegion, "Moesring Mountains Region" 30, 15, 0, 30, 0, 0, 0, 0, 10, 15 ModRegion, "Molag Mar Region" 35, 20, 25, 15, 0, 0, 5, 0, 0, 0 ModRegion, "Mournhold Region" 50, 40, 0, 5, 0, 5, 0, 0, 0, 0 ;ModRegion, "Red Mountain Region" 0, 0, 0, 0, 0, 0, 0, 100, 0, 0 ModRegion, "Sheogorad" 45, 30, 0, 15, 5, 5, 0, 0, 0, 0 ModRegion, "Thirsk Region" 40, 20, 10, 20, 5, 0, 0, 0, 5, 0 ModRegion, "West Gash Region" 45, 35, 5, 5, 5, 5, 0, 0, 0, 0 Set SeasonMonth to MonthElseIf ( Month == 8 ) ModRegion, "Ascadian Isles Region" 45, 45, 0, 0, 5, 5, 0, 0, 0, 0 ModRegion, "Ashlands Region" 20, 25, 10, 20, 0, 0, 25, 0, 0, 0 ModRegion, "Azura's Coast Region" 40, 35, 5, 10, 5, 5, 0, 0, 0, 0 ModRegion, "Bitter Coast Region" 20, 40, 5, 20, 10, 5, 0, 0, 0, 0 ModRegion, "Brodir Grove Region" 25, 30, 25, 20, 0, 0, 0, 0, 0, 0 ModRegion, "Felsaad Coast Region" 35, 15, 15, 15, 0, 0, 0, 0, 15, 5 ModRegion, "Grazelands Region" 35, 45, 5, 5, 5, 5, 0, 0, 0, 0 ModRegion, "Hirstaang Forest Region" 30, 40, 0, 30, 0, 0, 0, 0, 0, 0 ModRegion, "Isinfier Plains Region" 20, 20, 0, 25, 0, 0, 0, 0, 20, 15 ModRegion, "Moesring Mountains Region" 15, 10, 0, 30, 0, 0, 0, 0, 20, 25 ModRegion, "Molag Mar Region" 10, 15, 35, 25, 0, 0, 15, 0, 0, 0 ModRegion, "Mournhold Region" 30, 35, 5, 15, 10, 5, 0, 0, 0, 0 ;ModRegion, "Red Mountain Region" 0, 0, 0, 0, 0, 0, 0, 100, 0, 0 ModRegion, "Sheogorad" 25, 45, 5, 15, 5, 5, 0, 0, 0, 0 ModRegion, "Thirsk Region" 35, 20, 15, 15, 0, 0, 0, 0, 10, 5 ModRegion, "West Gash Region" 25, 35, 10, 20, 5, 5, 0, 0, 0, 0 Set SeasonMonth to MonthElseIf ( Month == 9 ) ModRegion, "Ascadian Isles Region" 45, 45, 0, 0, 0, 5, 5, 0, 0, 0 ModRegion, "Ashlands Region" 10, 25, 10, 25, 0, 0, 30, 0, 0, 0 ModRegion, "Azura's Coast Region" 25, 45, 10, 10, 5, 5, 0, 0, 0, 0 ModRegion, "Bitter Coast Region" 10, 60, 10, 0, 10, 10, 0, 0, 0, 0 ModRegion, "Brodir Grove Region" 20, 25, 35, 20, 0, 0, 0, 0, 0, 0 ModRegion, "Felsaad Coast Region" 30, 10, 15, 15, 0, 0, 0, 0, 20, 10 ModRegion, "Grazelands Region" 30, 40, 5, 5, 10, 10, 0, 0, 0, 0 ModRegion, "Hirstaang Forest Region" 20, 40, 0, 40, 0, 0, 0, 0, 0, 0 ModRegion, "Isinfier Plains Region" 10, 10, 0, 30, 0, 0, 0, 0, 30, 20 ModRegion, "Moesring Mountains Region" 10, 10, 0, 20, 0, 0, 0, 0, 20, 40 ModRegion, "Molag Mar Region" 5, 15, 35, 25, 0, 0, 20, 0, 0, 0 ModRegion, "Mournhold Region" 25, 35, 5, 20, 10, 5, 0, 0, 0, 0 ;ModRegion, "Red Mountain Region" 0, 0, 0, 0, 0, 0, 0, 100, 0, 0 ModRegion, "Sheogorad" 15, 40, 10, 15, 10, 10, 0, 0, 0, 0 ModRegion, "Thirsk Region" 20, 20, 30, 20, 0, 5, 5, 0, 0, 0 ModRegion, "West Gash Region" 15, 30, 15, 20, 10, 10, 0, 0, 0, 0 Set SeasonMonth to MonthElseIf ( Month == 10 ) ModRegion, "Ascadian Isles Region" 40, 45, 0, 0, 5, 5, 5, 0, 0, 0 ModRegion, "Ashlands Region" 5, 20, 15, 30, 0, 0, 30, 0, 0, 0 ModRegion, "Azura's Coast Region" 20, 35, 10, 10, 20, 5, 0, 0, 0, 0 ModRegion, "Bitter Coast Region" 10, 45, 10, 0, 25, 10, 0, 0, 0, 0 ModRegion, "Brodir Grove Region" 15, 20, 25, 20, 8, 0, 0, 0, 10, 2 ModRegion, "Felsaad Coast Region" 25, 11, 17, 15, 0, 0, 0, 0, 20, 12 ModRegion, "Grazelands Region" 20, 35, 7, 8, 19, 10, 0, 0, 1, 0 ModRegion, "Hirstaang Forest Region" 20, 35, 5, 25, 8, 0, 0, 0, 5, 2 ModRegion, "Isinfier Plains Region" 8, 8, 0, 30, 0, 0, 0, 0, 34, 20 ModRegion, "Moesring Mountains Region" 8, 8, 0, 22, 0, 0, 0, 0, 22, 40 ModRegion, "Molag Mar Region" 4, 5, 36, 30, 0, 0, 25, 0, 0, 0 ModRegion, "Mournhold Region" 20, 35, 7, 20, 13, 5, 0, 0, 0, 0 ;ModRegion, "Red Mountain Region" 0, 0, 0, 0, 0, 0, 0, 100, 0, 0 ModRegion, "Sheogorad" 10, 25, 15, 20, 15, 10, 0, 0, 4, 1 ModRegion, "Thirsk Region" 25, 11, 17, 15, 0, 0, 0, 0, 20, 12 ModRegion, "West Gash Region" 10, 25, 15, 20, 17, 12, 0, 0, 1, 0 Set SeasonMonth to MonthElseIf ( Month == 11 ) ModRegion, "Ascadian Isles Region" 20, 29, 5, 10, 25, 5, 5, 0, 1, 0 ModRegion, "Ashlands Region" 5, 10, 15, 24, 5, 0, 40, 0, 1, 0 ModRegion, "Azura's Coast Region" 20, 35, 10, 10, 19, 5, 0, 0, 0, 1 ModRegion, "Bitter Coast Region" 5, 10, 15, 20, 40, 10, 0, 0, 0, 0 ModRegion, "Brodir Grove Region" 5, 10, 25, 30, 0, 0, 0, 0, 27, 3 ModRegion, "Felsaad Coast Region" 10, 8, 20, 22, 0, 0, 0, 0, 25, 15 ModRegion, "Grazelands Region" 10, 20, 10, 18, 27, 10, 0, 0, 4, 1 ModRegion, "Hirstaang Forest Region" 10, 20, 10, 30, 8, 0, 0, 0, 15, 7 ModRegion, "Isinfier Plains Region" 5, 5, 0, 30, 0, 0, 0, 0, 38, 22 ModRegion, "Moesring Mountains Region" 5, 5, 0, 20, 0, 0, 0, 0, 27, 43 ModRegion, "Molag Mar Region" 4, 0, 36, 33, 2, 0, 25, 0, 0, 0 ModRegion, "Mournhold Region" 10, 24, 10, 25, 25, 5, 0, 0, 1, 0 ;ModRegion, "Red Mountain Region" 0, 0, 0, 0, 0, 0, 0, 100, 0, 0 ModRegion, "Sheogorad" 5, 20, 5, 20, 20, 10, 0, 0, 15, 5 ModRegion, "Thirsk Region" 10, 8, 20, 22, 0, 0, 0, 0, 25, 15 ModRegion, "West Gash Region" 5, 15, 15, 25, 25, 10, 0, 0, 5, 0 Set SeasonMonth to MonthElse ( Month == 12 ) ModRegion, "Ascadian Isles Region" 10, 10, 5, 10, 42, 15, 5, 0, 3, 0 ModRegion, "Ashlands Region" 1, 5, 0, 30, 5, 5, 50, 0, 4, 0 ModRegion, "Azura's Coast Region" 5, 15, 20, 27, 25, 5, 0, 0, 3, 0 ModRegion, "Bitter Coast Region" 4, 5, 5, 20, 60, 5, 0, 0, 1, 0 ModRegion, "Brodir Grove Region" 5, 5, 20, 30, 0, 0, 0, 0, 35, 5 ModRegion, "Felsaad Coast Region" 2, 3, 5, 25, 0, 0, 0, 0, 45, 20 ModRegion, "Grazelands Region" 5, 10, 5, 18, 52, 5, 0, 0, 4, 1 ModRegion, "Hirstaang Forest Region" 5, 10, 10, 30, 0, 0, 0, 0, 30, 15 ModRegion, "Isinfier Plains Region" 1, 3, 0, 26, 0, 0, 0, 0, 45, 25 ModRegion, "Moesring Mountains Region" 2, 3, 0, 20, 0, 0, 0, 0, 30, 45 ModRegion, "Molag Mar Region" 1, 0, 25, 35, 5, 0, 34, 0, 0, 0 ModRegion, "Mournhold Region" 5, 23, 10, 25, 30, 5, 0, 0, 2, 0 ;ModRegion, "Red Mountain Region" 0, 0, 0, 0, 0, 0, 0, 100, 0, 0 ModRegion, "Sheogorad" 1, 9, 5, 20, 20, 10, 0, 0, 25, 10 ModRegion, "Thirsk Region" 5, 5, 10, 30, 0, 0, 0, 0, 35, 15 ModRegion, "West Gash Region" 5, 5, 10, 35, 35, 5, 0, 0, 5, 0 Set SeasonMonth to MonthendIfEnd SeasonWeatherScript
It's pretty simple, and if you want to use it you can. You can modify it pretty easily if you feel that there should be more snow in Vivec in Last Seed (July) or something...