More sun, higher UV risk

A Europe-wide study with major involvement from the University of Veterinary Medicine Vienna (Vetmeduni) shows that skin-effective UV radiation has increased noticeably at many locations across Europe between 2013 and 2022. Clear increases were measured at 26 of 40 monitoring stations - a trend that is increasingly affecting everyday life and sun protection.

Photo: Shutterstock

More sunshine in Europe increasingly also means more skin-effective UV radiation - with consequences for daily life and health. A new analysis of 40 stations shows significant increases at 26 sites from 2013 to 2022, with a median rise of about 1.2 percent per year. Given an average daily dose of around 14 SED, this corresponds to roughly 0.17 SED per year, or a total of about 1.7 SED over the decade.

Note: SED (Standard Erythema Dose) quantifies exposure to the sun’s carcinogenic ultraviolet radiation - that is, the sunburn-inducing component.

Regional patterns

Values are increasing most strongly in Central Europe, while Northern and Southern Europe show more moderate rises and parts of the Iberian Peninsula show hardly any increase. On a monthly basis, the most pronounced increases often occur in January, February, and June; depending on the month, they typically range from 2 to 4 percent per year. What matters is less a uniform rise across all months than the marked increase in specific months. “Our measurement series show a widespread, yet regionally variable, increase in UV - the patterns are consistent with trends in global solar radiation from satellite data,” says Alois Schmalwieser of the Unit of Medical Physics and Biophysics at Vetmeduni.

Decline in cloudiness as the main driver

The primary driver is reduced cloud cover: where sunshine duration increases, ground-level UV usually rises in step - an observation supported by satellite-based datasets on global solar radiation. Aerosols and ozone played a subordinate role on average over the decade; time series of total column ozone show no Europe-wide decreases. In the winter half-year, relative increases are often largest in northern countries, yet summer remains decisive in absolute terms: “Even if the percentage increases are sometimes greatest in winter, summer is still the crucial season for health protection because it contributes the largest share of the annual UV dose,” Schmalwieser emphasizes. In the Alpine region, topography and snow cover amplify spatial variability; the close agreement between ground measurements and high-resolution satellite maps argues for real, regionally consistent signals.

Implications for public health include potentially higher risk, for example for non-melanoma skin cancer. Continuous, quality-assured monitoring, dense measurement networks, and adapted prevention are therefore needed. The analysis is based on daily, erythemally weighted UV doses under all-sky conditions, supplemented by satellite data on UV, global solar radiation, and sunshine duration; together, these enable precise local trends and the detection of large-scale patterns.

*erythema-inducing (sunburn-causing)

The article "Recent increases in solar UV radiation across Europe: a 40-location study to identify trend boundaries" by Schmalwieser, A.W., Lorenz, S., Klyshkina, D. et al. was published in Photochem Photobiol Sci.

Scientific article

Scientific contact:

Dr. Alois Schmalwieser
Medizinische Physik und Biophysik
Veterinärmedizinische Universität Wien (Vetmeduni)
Alois.Schmalwieser@vetmeduni.ac.at

To the Top