Rating of the UV Radiation Index

Time:2019/05/27 09:08:00 Browse:403

The level of ultraviolet radiation index in the weather forecast is divided into four levels: weak, medium, strong and extremely strong. When you have to go out when the index is strong, be sure to take protective measures.

You may not know that the ultraviolet radiation is very strong on cloudy days in summer, and the cloud layer has almost no isolation for UVA ultraviolet rays. 90% of UVA UV rays can penetrate the clouds, and only a thick layer of rain clouds can block some of the UV rays. Although the ultraviolet rays on sunny days are strong, there are strong ultraviolet rays on cloudy days. Many people are unprotected, which can have bad consequences.

The ultraviolet index released in the weather forecast refers to the index which ultraviolet radiation reaching the surface around the ground at noon may cause damage to human skin. It is a forecast of the intensity of ultraviolet light. The intensity of ultraviolet radiation can also be judged based on the published UV index.

Sunlight ultraviolet rays can kill a variety of bacteria, prevent a variety of diseases, adjust and improve the nerves, endocrine, etc., But excessive exposure causes photochemical reactions, which are harmful to the skin, eyes and immune system. If the skin is exposed to the sun for a long time or many times, it will be sunburned, and it will show symptoms such as itchy, stinging, scaling, and even skin cancer.


According to the UV Index standards set by the "World Health Organization", the "World Meteorological Organization", and "the United Nations Environmental Organization", the range of the UV index is represented by 15 digits from 0 to 15. The higher the index, the greater the damage the UV radiation causes to human skin. In daily life, the ultraviolet intensity is usually divided into four levels: weak, medium, strong and extremely strong.

  1. Usually the nighttime UV index is 0, 1, 2, the weakest does not need to take protective measures.

  2. Level 3 and 4 can take appropriate protective measures.

  3. The index is between 3 and 6 (including 3 and 6), take some protective measures when going out, wear a sun hat, sunglasses and sun umbrella.

  4. The index is 7 to 9, avoid exposure to sunlight at 10 to 14 o'clock, remember to wear a sun hat, sunglasses and sun umbrella when going out.

  5. The index is very strong when it is greater than 10, we must take various effective protective measures when going out. The UV index is 15 in tropical, highland, and sunny days.