Year-to-Date Daily Maximum UV Index Graphs

The UV Index plots are based on ground-based measurements by Brewer spectrophotometers carried out by the Science and Technology Branch. The actual measurements are indicated by the red dots. Estimates of UV Index for clear sky no-snow conditions and “normal” pre-1980 total ozone values are shown by the blue line. Estimates of UV Index for clear sky no-snow conditions and each day's total ozone values are shown by the magenta line.