Our UV index

The sun's ultraviolet rays peak around noon from June through August in Pittsburgh.

Why it matters: That's when it's especially important to limit time in the sun and cover up.

• UV radiation causes sunburn and is a risk factor for skin cancer.

By the numbers: A UV index of 6-7 is the "high" range, 8-10 is "very high," and 11 and up is "extreme."

• Pittsburgh's average UV Index at noon during the summer months is 8.8.

Between the lines: Altitude, latitude, cloud cover, ozone level, time of day and seasons all factor into the UV index.

It's a myth that you can't get a sunburn when it's cloudy — and that you need to feel the sun's hot rays to get a sunburn.

• In reality, 80% of solar UV radiation can penetrate light cloud cover — and infrared heat is different from UV radiation (which you can't feel), according to the EPA.

A simple way to estimate your UV exposure: Look at your shadow.

• If it's shorter than you are (around midday), UV levels are higher and more likely to cause sunburn.