Chicago needs to stock up on sunscreen

Two essential things to grab before heading out the door this week are sunglasses and sunscreen. The week should feature abundant sunshine with mostly sunny skies expected nearly every day. Monday will see more of a mix of sun and clouds, but the rest of the week will be brighter.

The UV Index for Monday is 8 which falls in the "very high" category.

The EPA offers the following advice for when the UV index reaches this level:

Protection against sun damage is needed. If you need to be outside during midday hours between 10 a.m. and 4 p.m., take steps to reduce sun exposure. A shirt, hat and sunscreen are a must, and be sure you seek shade. Beachgoers should know that white sand and other bright surfaces reflect UV and can double UV exposure.


The UV index forecast is a prediction of the relative amount of ultraviolet rays that cause damage to the skin will make it to the earth's surface on a given day. The two types of UV radiation that can cause damage are UVA and UVB.  

Here's an explanation of the difference between them from the Skin Cancer Foundation:

Two types of UV light are proven to contribute to the risk for skin cancer:

  • Ultraviolet A (UVA) has a longer wavelength. It is associated with skin aging.
  • Ultraviolet B (UVB) has a shorter wavelength. It is associated with skin burning.

While UVA and UVB rays differ in how they affect the skin, they both do harm. Unprotected exposure to UVA and UVB damages the DNA in skin cells, producing genetic defects, or mutations, that can lead to skin cancer and premature aging. UV rays can also cause eye damage, including cataracts and eyelid cancers.

A prognostication with plenty of sunshine means there will be a lack of rain. The 7-day precipitation chances forecast bears this out. The next decent chance for rain is Friday night.

Be prepared with sunscreen that has a proper SPF, or sun protection factor.

Here are some guidelines from the FDA:

In general, the FDA recommends that you use broad spectrum sunscreen with an SPF of 15 or higher, even on cloudy days. In addition:

  • Apply sunscreen liberally to all uncovered skin, especially your nose, ears, neck, hands, feet, and lips (but avoid putting it inside your mouth and eyes).
  • Reapply at least every two hours. Apply more often if you’re swimming or sweating. (Read the label for your specific sunscreen. An average-size adult or child needs at least one ounce of sunscreen, about the amount it takes to fill a shot glass, to evenly cover the body.)
  • If you don’t have much hair, apply sunscreen to the top of your head or wear a hat.
  • No sunscreen completely blocks UV radiation. So other protections are needed, such as protective clothing, sunglasses, and staying in the shade.
  • No sunscreen is waterproof.

The UV Index forecast for Tuesday is also in the "very high" range. I expect the UV Index this week will be somewhere between high and very high every day through Friday.

Despite all the sunshine that should be coming this week, there won't be any extreme heat to go along with it. Thursday and Friday will be the warmest days as highs hit the lower 80s. That would be right around average for the middle of August.