UV index world map, month by month
See how strong the midday sun gets anywhere on Earth, in any month. The map shows the UV index of each month's strongest days. Ordinary days are a little lower, usually within the same colour band; only rare record days sit higher. Built from 17 years of satellite data (2004–2020).
Colours show the midday UV index on each month's strongest days. Uncoloured areas: midday UV stays below 1. All values are for clear skies; clouds usually lower the UV you actually receive.
Based on TEMIS data. Copyright © KNMI/ESA — https://www.temis.nl/
In October the strong sun is in the southern hemisphere: UV reaches high levels across most of it, while the northern hemisphere outside the tropics has its mild season. The highest values, up to UV 19, occur over the high Andes: thin high-altitude air filters out far less UV.
UV world map for every month
Frequently asked questions
Why does the strong-UV zone move during the year?
The belt of strong UV follows the sun. In June and July the sun stands highest over the northern hemisphere, in December and January over the southern one, so the red and purple areas shift back and forth across the equator with the seasons. Near the equator itself the sun stays high all year, which is why UV there is strong in every month. High mountain ranges stand out in every season: the air above them is thinner and filters out less UV.
Where does the data for these maps come from?
The maps are built from satellite-derived clear-sky UV data produced by KNMI and ESA in the TEMIS project. For every place on a world grid, seventeen years of daily values (2004–2020) give a typical level and a year-to-year spread for each day of the year; the map shows the level of the month's strongest days on cloud-free days. Single record days sit higher and are left out. Clouds usually lower the UV you actually receive.
How do I check the UV at a place I'm travelling to?
Search for the city in the box above. Every city page on UVI.today has its own month-by-month UV overview based on the same satellite data, shown next to the live UV index and the forecast for the coming days, so you know what to expect before you go.
For the UV index right now and the days ahead, open the live UV map. The methodology page explains how these values are produced and how the monthly maps differ from the live forecast.
