The SUM06 is the sum of the ozone concentrations for every hour that exceeds 0.06 parts per million (ppm) within a 12-hour period from 8 am to 8 pm in the months of May to September.
The SUM06 is the sum of the ozone concentrations for every hour that exceeds 0.78 parts per million.
The SUM06 isn't the sum of the ozone concentrations for every hour that exceeds 0.78 parts per million.