UV Index


Definition: The UV Index is a measure of the amount of skin damaging UV radiation expected to reach the earth's surface at the time when the sun is highest in the sky (around midday).

The UV Index for India is developed and proposed by the Ministry of Earth Sciences (MoES) after extensive research work based on the analysis of the time series of long term stratospheric ozone data and carrying forward from the guidelines of World Health Organization (WHO). The UV Index provides the expected risk of overexposure to the sun. The Index give UV intensity levels on a scale of 1 to 10+, where 1 indicates a low risk of overexposure and 10+ signifies an extreme risk.

UV-Index for India defined by MoES (IITM)

For Ultra-Violet – radiation and related health advisory:

Sr. No. Range of UV- Index Risk Level Health Advisory
1) 1 to 4 No-Risk No health risk to General public
2) 5 Low Risk Little risk of harm from unprotected sun exposure. It is advisable to use UV-protective accessories for sensitive people, general public less likely to be affected.
3) 6 to 9 Medium Sensitive people are at medium risk of harm from direct exposure to sun. It is advisable to use UV-protective accessories by general public as well.
4) 10 Onwards High Risk All people are at high risk of harm. It is advisable to avoid direct sun exposure.

We all wish to have sunlight. In summer the sun bites us whereas in winter sunlight can be enjoyable. However, too much exposure to sun could be dangerous. Overexposure to the sun’s ultraviolet (UV) radiation can cause immediate effects, such as sunburn, and long-term problems, such as skin cancer and cataracts even if you have dark skin colour. The amount of UV radiation reaching the surface is primarily related to the elevation of the sun in the sky, the amount of ozone in the stratosphere, and the amounts of cloud cover. However, thick cloud can greatly reduce ultraviolet radiation levels and, surprisingly, certain types of thin cloud can magnify the ultraviolet radiation strength.

Exposure Level Attributes:

No risk means that there is nothing to worry about - the sun will not harm you.

Low risk means that the sun is not dangerous, but you should avoid being in direct sunlight for more than 1 to 2 hours. Redness (erythema) will occur after longer exposition. People should consider wearing UV-A+B sun glasses

Medium risk means sun could be dangerous. Try to keep out of direct sunlight, cover up or wear a sunscreen lotion SPF 15+. Use protective clothing.

High risk means that you could burn severely in few hours. Stay out of direct sunlight, cover up and use a sunscreen lotion SPF 15+.

UN-Index and Preventive Steps

By adopting a few simple precautions daily, you can greatly reduce your risk of sun-related illnesses. This problem is most severe during summer in India. These steps are as follows:

             • Do Not Burn

             • Avoid Sun Tanning and Tanning Beds

             • Generously Apply Sunscreen with an SPF of at least 15

             • Wear Protective Clothing, Including a cap, Sunglasses, and Full-Length Clothing

             • Seek Shade as much as you can afford in your daily routine.

             • Use Extra Caution Near Water, Snow and Sand

             • Watch for the UV Index

             • Get Vitamin D Safely