‘Tis the season! Trips to the pool, lake, and the beach are always fun ways to beat the heat, but can also result in skin damage if not properly prepped for the summer sun.
The UV (Ultraviolet) Index is a tool used to measure the harmful effects the sun can have on your skin. With many taking part in outdoor activities over the next few months, let’s break down the categories and how you can stay safe from the sun’s rays:
How is the UV Index calculated?
The National Weather Service (NWS) works alongside the Environmental Protection Agency (EPA) to forecast these numbers across the country on a daily basis.
The forecast takes into account various parameters such as ozone levels, cloud cover, and elevation, then relates them to the strength of solar ultraviolet radiation. On top of that, surface objects that reflect light (like water, sand, and even snow) can further amplify the UV Index as well.
UV Index Categories
There are five UV Index categories ranging from “low” to “extreme.” Here’s a breakdown of what each category means and the corresponding protection tips that you should take when each category is issued:
| UV Index | Protection Tips |
|---|---|
| 1-2 (Low) | Low danger from the sun’s UV rays • Wear sunglasses on bright days • If you burn easily, consider using an SPF 30+ sunscreen |
| 3-5 (Moderate) | Moderate risk of harm from unprotected sun exposure • Consider wearing a hat and sunglasses if planning on being out in the sun • Wear an SPF 30+ sunscreen • Find a shady spot during the midday hours |
| 6-7 (High) | High risk of harm from unprotected sun exposure -- protection is needed! • Limit time in the direct sun if possible, mainly between 10 a.m. to 4 p.m. • Wear a wide-brimmed hat, sunglasses, and at least an SPF 30+ sunscreen |
| 8-10 (Very High) | Very high risk of harm from unprotected sun exposure -- protection is needed! • Take frequent breaks in the shade, especially if outside between 10 a.m. to 4 p.m. • Wear a wide-brimmed hat, sunglasses, sunscreen of at least SPF 30+, and even a shirt if practical • If at the beach, take note that the white sand and water can reflect UV rays, doubling the exposure at times |
| 11+ (Extreme) | Extreme risk of harm from unprotected sun exposure -- protection is needed! • Take all of the precautions listed above, and be sure to re-apply sunscreen of at least SPF 30+ every 2 hours. • Unprotected skin can burn in minutes! |
Table information provided by the National Weather Service and the Environmental Protection Agency.
To find the latest daily and hourly UV Index forecast for San Antonio, click here.
It’s important to keep in mind that the highest forecasted UV Index value for the day is valid at solar noon, which is different than the actual noon hour. Solar noon reflects the time at which the sun is at its highest point of the day.
You can calculate today’s solar noon by visiting the link here.
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