UK — UV radiation levels are unusually high across much of the UK for this time of year, prompting public health warnings about sun exposure. Health experts emphasize that the current UV Index readings exceed typical seasonal norms, increasing risks of skin and eye damage even on cooler or cloudy days.

The UV Index, a global standard measuring ultraviolet radiation intensity, typically ranges from 5 to 6 during UK summers and reaches a maximum of 8 only in exceptional conditions. According to the World Health Organization, sun protection is required when UV levels are medium (3–5) or high (6–7), with extra precautions needed at very high (8–10) or extremely high (11+) levels. Current readings in parts of the UK have entered these elevated categories earlier than usual.

“Every exposure to UV, especially every sunburn, increases our risk of skin cancer,” says Prof Dorothy Bennett, from St George's, University of London. “Melanoma, the most dangerous skin cancer, is now the fifth commonest cancer in the UK.”

The NHS advises using sunscreen with SPF 30 or above and at least 4-star UVA protection, applied to all exposed skin—including face, neck, ears, and scalp if hair is thinning—ideally 30 minutes before going outside. Adults should use six to eight teaspoons to cover the entire body and reapply every two hours, or more frequently if sweating, swimming, or towel drying. Additional measures include wearing protective clothing, sunglasses, and seeking shade between 11:00 and 15:00 from March to October.

Dr Bav Shergill from the British Association of Dermatologists notes that tanning provides minimal protection. “When you tan, ultraviolet light stimulates your skin cells to produce pigment to try and protect the DNA of skin cells—but that protection is minimal—the equivalent of SPF 4.” “That is not much protection at all—so you can still burn very early,” he warns. He recommends self-tan products instead of UV exposure.

“Don't be caught out on cloudy days. UV will still penetrate thin clouds—so even if you don't think it's that sunny, you can still burn,” says BBC Weather presenter Helen Willetts.