About

Last updated 25 October 2026

uvatlas publishes the UV index for cities in Australia and the United States: what it is right now, how it changes through the day, and when sun protection is needed.

It exists because UV is the weather measurement you cannot feel. Heat, wind and rain announce themselves; ultraviolet does not, and the mild spring day that burns you looks exactly like the one that does not. A number and a time, on one page, is usually all anyone needs.

Who runs it

uvatlas is run by Keith Chester, independently, from the United Kingdom. It is not affiliated with ARPANSA, the US Environmental Protection Agency, Copernicus, or any health authority. Those organisations provide the underlying data under open licences; they have no involvement in this site and no responsibility for it.

Email contact@uvatlas.com.

How it is funded

The site currently carries no advertising and no sponsorship, and sells nothing. It may carry advertising in future; if it does, advertisements will be clearly separated from the readings, and this page will say so.

How it is built

Pages are generated on the server from open data sources, with no tracking and almost no JavaScript. The methods page lists every source, how often it is refreshed, and how accurate the forecast has measured out to be.