Spring UV Is Sneaky: Why March Sunburns Catch You Off Guard
Cool air paired with strong rays is the seasonal mismatch that burns people in March.
Visible light is ~45% of sunlight; UV is ~5-7%; infrared makes up the rest.
The Skin Cancer Foundation notes UVA passes through clouds and ordinary window glass.
Questions we get a lot
How does sunscreen actually work?
Sunscreens use UV filters in two groups. Organic ('chemical') filters such as avobenzone absorb UV and release it as a small amount of heat. Mineral ('physical') filters — zinc oxide and titanium dioxide — mainly absorb UV and also scatter some. Both cut how much UV reaches living skin cells.
What does the UV index mean and when should I protect my skin?
The UV Index, from the EPA and WHO, rates the strength of midday UV on a scale from 1–2 (low) to 11+ (extreme). Dermatologists generally advise sun protection whenever it reaches 3 or higher. It appears in most weather apps and rises with sun elevation, altitude and proximity to the equator.
Is visible light bad for skin?
Visible light makes up about 45% of sunlight. Research shows high-energy visible (blue) light can worsen pigmentation and melasma, especially in medium-to-deep skin tones. Tinted sunscreens containing iron oxides help shield against it, which clear sunscreens generally do not.
r/30PlusSkinCare: 'Is the UV index app on my phone actually accurate?'