Here's a summary on how the weather works. I can't give some information due to proprietary information (i.e. formulas) but this should help. I'll also be posting this on the AoD
Discord channel under Hints-Tips-and-strategies.
General Information:
Random Weather Duration:
• Average Weather Duration is 60 game hours
• Maximum Weather Duration is 144 game hours
Northern or Southern Hemisphere Determinations:
• Northern Hemisphere - It utilizes the province's City YPos column in the province.csv file. If the City YPos is less than 7200 then it returns true (the province is considered in the northern hemisphere).
• Southern Hemisphere - It utilizes the opposite of the northern hemisphere. If it's not northern hemisphere then it returns false.
Seasons - There are 4 seasons and within these 4 seasons the province's Climate column in the province.csv file further defines the season:
Spring:
• If the Climate column is Artic and in the northern hemisphere, then Spring begins on 1 May
• If the Climate column is Artic and in the southern hemisphere, then Spring begins on 1 November
• If the Climate column is Sub-Artic or Muddy and in the northern hemisphere, begins on 1 April
• If the Climate column is Sub-Artic or Muddy and in the southern hemisphere, begins on 1 October
• If the Climate column is Temperate and in the northern hemisphere, then Spring begins on 1 March
• If the Climate column is Temperate and in the southern hemisphere, then Spring begins on 1 August
Summer:
• If the Climate column is Artic and in the northern hemisphere, then Summer is 1 June through 30 September
• If the Climate column is Artic and in the southern hemisphere, then Summer is 1 May through 30 October
• If the Climate column is Sub-Artic or Muddy and in the northern hemisphere, then Summer is 1 May through 30 September
• If the Climate column is Sub-Artic or Muddy and in the southern hemisphere, then Summer is 1 November through 30 April
• If the Climate column is Temperate and in the northern hemisphere, then Summer is 1 April through 30 October
• If the Climate column is Temperate and in the southern hemisphere, then Summer is 1 September through 30 May
• If any other Climate then it's always summer.
Fall/Autumn:
• If the Climate column is Artic and in the northern hemisphere, then Fall begins on 1 September
• If the Climate column is Artic and in the southern hemisphere, then Fall begins on 1 March
• If the Climate column is Sub-Artic or Muddy and in the northern hemisphere, then Fall begins on 1 October
• If the Climate column is Sub-Artic or Muddy and in the southern hemisphere, then Fall begins on 1 May
• If the Climate column is Temperate and in the northern hemisphere, then Fall begins on 1 November
• If the Climate column is Temperate and in the southern hemisphere, then Fall begins on 1 June
Winter:
• If the Climate column is Artic and in the northern hemisphere, then Winter is 30 October through 1 April
• If the Climate column is Artic and in the southern hemisphere, then Winter is 30 April through 30 October
• If the Climate column is Sub-Artic or Muddy and in the northern hemisphere, then Winter is 1 November through 30 March
• If the Climate column is Sub-Artic or Muddy and in the southern hemisphere, then Winter is 30 April through 30 September
• If the Climate column is Temperate and in the northern hemisphere, then Winter is 30 December through 1 February
• If the Climate column is Temperate and in the southern hemisphere, then Winter is the month of July
Sub-Seasons/Climates:
Dry Season:
• If the province's Climate column in the province.csv file is Arid, then it's arid regardless of which hemisphere it's in.
• If the province's Climate column in the province.csv file is Mediterranean, then it's Mediterranean regardless of which hemisphere it's in.
• If the province is in the northern hemisphere then the dry season is 1 June through 30 September
• If the province is in the southern hemisphere then the dry season is 1 December through 30 March
Muddy Season - If it's spring in the province and province's Climate column in the province.csv file is Muddy, then it's muddy
Rain Season:
• If the province's Climate column in the province.csv file is Tropical and in the northern hemisphere, then 1 May through 30 November
• If the province's Climate column in the province.csv file is Tropical and in the southern hemisphere, then 1 October through 30 April
• If the province's Climate column in the province.csv file is Sub-Tropical and in the northern hemisphere, then 1 May through 30 November
• If the province's Climate column in the province.csv file is Sub-Tropical and in the southern hemisphere, then 1 June through 30 July
• If the province's Climate column in the province.csv file is Mediterranean and in the northern hemisphere, then 1 October through 30 February
• If the province's Climate column in the province.csv file is Mediterranean and in the southern hemisphere, then 1 May through 30 August
Other Sub-Seasons/Climates:
• Based on a random selection of 1 province that becomes the center for the start of climate/storm
• The climate/storm area is determine by a randomize formula (which can't be given out due to proprietary reasons)
• Some climate/storm types are seasonally (spring, summer, fall, winter) determined (i.e. blizzard, snow, frozen, etc.)