The Air Quality Index compiled by the Victorian Environment Protection Authority measures the concentration of various pollutants relative to the levels at which they may cause harm. The index is available for four areas in the Port Phillip Region (East, West, City and Geelong) and the Latrobe Valley.
The Visibility Pollutant Index is an indicator of visibility reduction. Visibility incidents are generally higher during cooler months of Autumn and Winter (from May to September), whereas ozone values are generally higher during warmer months of Spring and Summer (from November to February).
View underlying data as an Excel spreadsheet (zipped): 1367.2 Table 5, Air Quality, Pollutant and Visibility. (36kB)