UV Index 🇬🇧United Kingdom

The United Kingdom straddles the higher mid-latitudes between roughly 49° and 61°N on the western seaboard of Europe, which keeps the sun comparatively low even at the June solstice and clips winter sun-angles sharply. Its humid temperate oceanic climate (Köppen Cfb), shaped by frequent passage of the polar-front jet stream, brings cloudy skies on more than half of all days. Mean monthly UV index figures published by the Met Office peak at only around 6 in June and July across central and northern England before falling to 0 in midwinter.

What sets the UK apart is the extreme seasonal contrast in daylight at such an oceanic, cloud-prone latitude: at Aberystwyth (about 52°N) the sun is up for nearly 17 hours at the summer solstice but for just over 7.5 hours at midwinter, so the UV window collapses with the daylength. Ben Nevis rises to 1,345 m in the Scottish Highlands, where altitude raises clear-sky UV but persistent mist, fog and gales offset it; nationally the UK averages only 1,339.7 hours of sunshine a year — under 30% of the astronomically possible maximum.

The United Kingdom sits at #187 of 191 in the WHO's global ambient-UV ranking with about 1,576 J/m² of average daily UV, around the 2nd percentile worldwide.