According to the Tartu Observatory, the index measuring harmful ultraviolet radiation reaching the ground in Estonia hit a record 8.6 on June 29, clearly above the healthy level for habitual sunbathers.
Weather forecaster Ain Kallis told uudised.err.ee that ultraviolet radiation measurements are not comparable in accuracy to other meteorological data like temperature or wind speed, but that the current level is definitely exceptional for Estonia.
However, the amount of harmful radiation is expected to drop somewhat by Thursday, with more cloudy skies ahead.
When the index is above six on the 10-point scale, it is unadvisable to remain in the sunlight without covering up. Sunburn, which occurs on the average after less than 20 minutes of bare skin exposure at the 8.6 level, carries a risk of skin cancer.