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Beginner's guide to the UV Index: How to read it and why you should

Let's face it. There's a lot to love about the sun. What we don't like is the way its ultraviolet rays can damage our skin! That's why understanding how to read the UV Index is so important.

Here's the skinny on the UV Index and why you should read it every day.

What is the UV Index?

The UV index predicts how fast you will burn without the right sun protection. Checking it daily is a great way to protect your skin.

The Environmental Protection Agency and the National Weather Service work together to develop the UV Index. It helps you plan outdoor activities without harming your skin.

Scientists use a computer model to measure how strong the daily ultraviolet rays are. The higher the index number, the greater your risk of getting a burn when not protecting your skin by wearing quality sun protection.

How do scientists determine the UV Index?

Scientists use many factors to determine how strong the UV rays will be on a given day.

1. Ozone level

Ozone is a good thing as it absorbs harmful UV rays and makes them less intense. The more ozone, the lower the index will be. The amount of ozone exposure fluctuates every day.

2. Time of day

The higher the sun is overhead, the more UV rays hit you. This means the UV Index is going to be at its highest between noon and 1 p.m., also known as "solar noon." Those rays won't be as intense at other times of the day ‚ÄĒ but are still there.

3. Season

As you can imagine, the UV Index is highest during¬†the warm, sunny¬†days of spring and summer. The index will be lower during the fall and¬†winter months ‚ÄĒ but can still be strong, depending on the day.

4. Cloud cover

A good, thick cloud cover can lower the UV index, but you're still exposed to significant UV radiation on cloudy days. In fact, paradoxically, sometimes clouds can actually increase the amount of UV radiation we're exposed to.

5. Anything coating the earth's surface

Anything covering the Earth's surface can reflect and scatter UV radiation and make the index more intense. Think snow or water, for example. Snow can scatter up to 80% of those rays, while the water reflects 10%. White sand can also scatter rays and increase their intensity.

6. Land cover

Buildings and trees will block the harmful rays of the sun and lower the index number. If you're outside without sun protection, duck into the shade as much as you can.

7. Latitude

Your location makes a big difference as well. If you're closest to the equator, the UV Index will be the highest. The further you travel closer to either the North or the South Pole, the lower that number gets.

How do I read the UV Index?

The lower the UV Index number, the more time you can spend outside without sun protection before you get a sunburn (but it doesn't mean you should!).

Here's what the different numbers mean.

The UV Index is from 0 to 2

You only get a low level of UV rays when the UV Index is between 0 and 2, and your risk of getting a sunburn is less than at other levels. These are the safest times to be out in the sun, although sun protection of SPF 30 or higher is still important during the day, and it's still possible to get sunburns when the UV index is low.

The UV Index is from 3 to 5

When the UV Index is from 3 to 5, there is a moderate chance of getting a sunburn. The EPA recommends you keep to shady spots, especially from late morning through mid-afternoon. Wear UV protective clothing along with a hat or visor and sun protection of SPF 30 or higher.

The UV Index is from 6 to 7

When the UV Index gets up to 6 or 7, you should limit your time in the sun if you're not wearing sun protection. The average person can get a burn after only 15 to 25 minutes in the sun.

When the level is this high, wear a hat, sunglasses, and protective clothing. Apply sun protection with an SPF of 30 or higher at least every two hours, and stay out of the sun between 10am and 4pm.

The UV Index is from 8 to 10

When the UV Index gets between 8 and 10, things are getting serious. No matter what type of skin you have, spending even 10 minutes without sun protection could give you a sunburn. Protective clothing, a hat, and sunglasses are a must along with sun protection of SPF 30 or higher.

The UV Index is 11 or higher

A UV Index of 11 or higher is downright dangerous. Go without sun protection, and your skin can burn in minutes. You'll need all the protection you can get at this level.

No matter what the level is, wearing sun protection of SPF 30 or higher is a must.

Why should I read the UV index?

You may still wonder why you should read the UV Index every day. Like many people, you might underestimate the dangers of sun exposure. Whether you experience a sunburn or not, exposure to UV radiation is cumulative and can lead to skin damage, premature aging, eye problems, and even skin cancer.


What can I do to protect myself?

You can take steps to reduce your risk of experiencing harmful health effects from sun exposure.

Check the UV Index daily

Look at the UV Index every day so you can properly prepare for your time outside. If you have an iPhone or an iPad, you can find the UV Index in your area through the Apple weather app. If you wear an Apple Watch, you'll be able to see the UV Index there.

If your phone is an Android device, you can look up the UV Index by searching the weather forecast on your Google app.

The Weather Channel also has an app for most devices, including Android. Better still, look for a UV Index app that will send you notifications when the UV levels are dangerous for your skin type.

Protect your skin

Wear sun protection with an SPF of 30 or higher every day, even if it's cloudy outside. Apply it to your skin 15 to 30 minutes before you go outside. You also want to protect your lips by wearing lipstick or lip balm that has an SPF of 30 or higher.

Reapply your sun protection at least every two hours. If you're sweating or in the water, reapply it every hour. 

Don't forget the accessories

Get into the habit of putting on a hat every time you go outside. If you get tired of wearing a baseball hat, shake things up. Wear a wide-brimmed hat instead, or switch to a visor. You can also wear a colorful scarf.

Make sure every pair of sunglasses you wear provide you with sufficient UV protection so your eyes stay healthy.

How can the UV Index help me?

Knowledge is power. When you know about the UV Index and understand how to read it, you'll be prepared to protect your skin from harmful UV rays and avoid sunburns. Plus, you'll reduce your likelihood of premature aging and other health problems. You can avoid skin cancer and other skin conditions. You'll also protect your vision.

Act now to protect your skin by buying high-quality sun care products that nourish your skin and feel great. That way, you'll have a natural glow and confidence that your skin will remain strong and healthy for years to come.