You wake up in the morning, grab your phone and check the weather. It is a sunny day in winter, and as you scroll down for details, you see something called "UV Index," which--lucky you--is 0 today! No sunscreen necessary, right?
Sorry, but wrong. If you want to protect your skin from skin cancer and premature aging, you need to wear sunscreen every day, regardless of the weather. Remember that 80% of UV rays make it to your skin on a cloudy day, and most of them are UVA, the rays that cause visible signs of aging. (Both UVA and UVB exposure can lead to skin cancer.)
If your only concern is sunburn, the UV Index is helpful, but the sun also causes invisible damage. According to the AIM at Melanoma Foundation the Index rates the risk of overexposure to the sun. Index Levels 0-2 are considered Low Risk, but the foundation recommends that you still protect your skin and eyes with sunscreen (SPF 30 or higher) and sunglasses. Levels 3-5 are Medium Risk, and in addition to sunscreen and sunglasses, your protection should include a hat. High Risk (Levels 6-7) and Very High Risk (Levels 8-10) mean you should use all 3 of those protections, plus seek shade. Extreme Risk (Level 11+) means that you should take all of the previously mentioned precautions and stay indoors between 10 am and 4 pm.
The Foundation also notes that most people can tolerate up to one hour of sun at Index Levels 0-2 without negative visible effects, but those with fair skin should not be out without protection for even that length of time. (Keep in mind, this is just burning, not aging effects.) And everyone, regardless of skintone, should use all precautions recommended if they will be outdoors for more than one hour throughout the day. (Sun exposure is cumulative, taking a break and going indoors does not start the "exposure" clock over again.)
To be sure your skin is protected from sunburn AND premature aging, take your BRUSH ON BLOCK® Mineral Sunscreen SPF 30 and Protective Lip Oil SPF 32 with you where ever your day takes you. And remember, #dontfryreapply!