By 1994, many countries had followed NZ's lead, and were providing UV information to the public. Unfortunately, many different and sometimes conflicting indices were in use. The WMO recommended in 1994 that countries should adopt a standardised UV index. 52.6 8.2 3.3 0.2 2.7 Scott Base 77.9 2.9 0.3 0.0 0.6 Table 1. Typical clear-sky UV indices over New Zealand and its surrounding region.
Seasonal variations are larger at high latitudes.
The long term aim is that individuals will be able to assess what the index means for them in the same way as we assess temperature. As an approximate guideline in the interim, a UV index of 12 approximately corresponds to a burn time of 12 minutes. This algorithm gives 36 hour global predictions of the UV index, and includes predicted changes in ozone fields in response to dynamical changes. There is also the potential to include effects of predicted cloud cover. There is a significant public health risk from UVB exposure which is reduced by increased public awareness of the danger.