This summer I spent 88 consecutive days in Estepona from June 8th to September 6th. I would like to go back October 31st but I am unsure of the rules. Do I have to be out of the country for 6 months after September 6th or did coming back to Chicago for 2 months satisfy the 180-day law?
Unless you get a long-stay visa or residence permit from one of the Schengen countries, you cannot enter the area at any time when you have been inside for 90 of the past 180 days.
This means in particular that after spending 90 consecutive days on the Schengen area, you need to say outside for 90 entire days before you can enter again.