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Environment Canada
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Year-to-Date Total Ozone Graphs

The graphs show daily mean total ozone values (in Dobson Units) as a function of the season over Canadian stations for the current year up to yesterday. The results of most accurate Brewer direct sun measurements are shown in red, all other types of data are shown in blue. The green line indicates total ozone values smoothed by one month running mean. The dashed lines represent “normal”, pre-1980 total ozone annual cycle and two standard deviations envelope for daily mean total ozone. The actual data are available (typically, with one month delay) from the World Ozone and Ultraviolet Radiation Data Center (WOUDC).

Mauna Loa
Goose Bay
To find plots for previous years visit our FTP site at