UV and ozone

Check out UV index forecasts for locations in New Zealand (including ski fields), Australia, the Pacific and Antarctica.

Today's UV Index

The UV Index is a measure of the intensity of UV radiation. The UV Index supersedes the idea of "Time to Burn" or "Burn Time", which has been used previously in New Zealand.

Plots of UV levels throughout the day at different locations.

NIWA has developed a real time UV display in consultation with the Cancer Society and Sunsmart.

CFCs have damaged the ozone layer and led to higher UV levels and increased health risks. Our role is to understand the causes and effects of ozone depletion, to inform the public of the risk.

Several apps that provide forecasts of the UV index (UVI) are available for smartphones. 

There is a marked seasonal cycle in surface ozone (O3), with a maximum in winter and minimum in summer. There can also be significant variability from day to day caused by synoptic scale meteorological variations.

This research project focusses on modelling atmospheric chemistry and climate from the surface to the top of the stratosphere, using sophisticated chemistry-climate models.

This information is provided as part of our UV Ozone service, which also includes ozone and UV maps for New Zealand, yesterday’s forecast and measured UV, UV Atlas software, and more. NIWA has also developed an instrument to measure UV levels and display the UV Index on an easy-to-read dial. This is intended for use at swimming pools, outdoor sports events, and so on. The measured UV Index can be affected by cloud cover at Lauder.

Find out more about our national UV workshops