Although UV levels are higher during summer than they were today, UV levels were obviously abnormal for this time of year, and with fine weather expected throughout much of the country, a general warning was issued to media by the National Institute of Water and Atmosphere research (NIWA).

Further details can be found here:

Skiers in particular were warned of the high UV levels as the combination of higher altitude and reflectivity of the snow increased the effects of the ozone “tear.” Fortunately though in Wellington, it was not really an issue with thick cloud and fog obscuring any look at the sun, along with strong winds, making outside activities a little unpleasant!