What is the UV Index?

uv indexClouds don’t protect you from the sun

On a cloudy summer day it’s easy to forget that the sun’s skin-damaging ultraviolet or UV rays aren’t blocked by the clouds. We still have to use sunscreen, wear hats and sunglasses, or stay out of the sun to protect ourselves.

Related post: Be informed – What is SPF?

UV rays not only cause sunburn, but also skin cancer and cataracts. And there aren’t enough beauty creams in the world to undo the premature aging effects of the sun, either.

Watch this video to see the sun’s “invisible” damage to the skin.

It definitely motivated me to be more careful!

The UV Index

Rather than depending on how clear the skies are, scientists developed the UV index as a measurement of the strength—the damaging effect—of the sun’s ultraviolet rays. A zero rating is very low, while a rating greater than 8 is very high.

A low rating of 0-2 means a low danger from exposure to the sun’s UV rays, at least for the average person.

A very high rating of 8-10 means a high risk of sun damage to anyone not protected from the UV rays.

Ratings change hourly; the highest rating of the day is always at noon.

The purpose of the UV index is to help us protect ourselves from the sun. If we know when the UV rays are going to be strongest, we can better prepare for the day’s activities.

Get the UV Index appuv index

An app I like and use is the SunWise UV Index app put out by the Environmental Protection Agency (EPA).

(Get the Android version here.)

Living in a perpetually cloudy part of the country, I admit I get a little lazy about using sunscreen. If I can quickly check my local UV index, and know that it’s going to be high (it’s going to be an 8 today, even though it’s overcast!) I’m much more likely to use sunscreen and be more careful.

The app not only forecasts the UV index for your location (by area code), it also explains what the different rating levels mean, and the sun safety measures you should take.

For example, the app warns me about being near the beach or water: “bright surfaces reflect UV and can double UV exposure.”

Good to know.

I think the UV index is a great way to visualize the sun’s danger and be reminded and encouraged to use common sense precautions.


Frugal Nurse


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