Real-time UV Index displays

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

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

The first prototype is currently installed at the new Molyneux Aquatic centre in Alexandra. Current UV intensities are sensed by a detector designed to measure the sun burning UV from the sun and sky that is incident on a horizontal surface. The signal is amplified and then displayed by means of servo technology that is used in model aircraft.

A large pointer displays the current intensity of UV, in terms of the internationally agreed UV Index scale. The scale is subdivided into 5 different regions corresponding to 5 different behavioural responses. For UVI values less than 3, the risk is “low” and the colour code is green. UVI values exceeding 10 are designated as “extreme” and colour-coded purple.

The display is solar powered, making it useful for outdoor sporting events (e.g., tennis, cricket, athletics, etc). We are seeking sponsors to cover the costs of calibrations. The UVI scale was originally used in Canada, where its maximum value was designed to reach 10. In New Zealand, the peak UVI can exceed 13 near midday in summer.

Basic units like the one shown here would cost about $3000. We are currently investigating other options including larger versions and double sided versions, and solar powered versions. All units would be offered with the option of an additional maintenance contract, which would include calibration of the display. All units would include the NIWA and Sunsmart logos, but there are spaces for two other advertisers (to effectively pay for the maintenance fee).


1. We no longer manufacture these devices. However, one is available for short-term lease.

2. Please contact us if you wish to purchase technical specifications and drawings so that you can manufacture them yourselves.

3. We now consider that developing and using smart phone UVI Apps would be a better alternative. Such Apps could provide the current UVI at the phone's location, and the predicted course of UVI over the course of the day. More information at UVI forecast for Specific Sites.