The ranges
The commonly used scale describes 0–2 as low, 3–5 as moderate, 6–7 as high, 8–10 as very high, and 11 or more as extreme. Local agencies may present guidance in slightly different formats.
Why temperature is not enough
UV can be high on a cool or cloudy day. Time of day, season, latitude, elevation, cloud conditions, and reflective surfaces all affect exposure.
Practical planning
When UV is elevated, consider shade, protective clothing, and eye protection, and follow guidance from a trusted public health or weather authority. This guide is general information, not medical advice.
What this means for your day
Check UV separately from temperature when planning time outdoors, especially around midday or reflective surfaces.
Frequently asked questions
Why does the uv index change?
Weather information updates as new observations and forecast model runs become available. Small changes are normal, especially farther into the future.
Where can I see this information?
Use Weather Chase's current conditions, hourly forecast, daily forecast, and map tools to compare the latest information for a location.