Historical measurements of surface ozone in the Southern Temperate region (30°S–60°S; see Table 6 for details). Error bars represent standard deviations of the measurement averages (atmospheric variability), not uncertainty of the measurement. Five-year averages (daytime mean) of modern UV measurements at sites below 2000 m, classified as “rural”, in the TOAR 5 × 5 degree gridded average product are also shown, for both daytime averages (day) and daily 8-hour maxima (DMA8) (Schultz et al., 2017). DOI: https://doi.org/10.1525/elementa.376.f6