WHEN DO I NEED TO USE SUNSCREEN?
Every day. UV rays penetrate cloud cover and most glass, so it makes sense to wear sunscreen even if it’s overcast or cool, or if you spend a lot of time driving or indoors near a window or under a skylight. Sunscreen also works best when it has had time to be absorbed. Apply it 15 minutes before going outdoors, and don’t forget to take it with you so you can reapply as needed (every two hours, or sooner if you’ve been sweating or swimming).
Most labels will instruct you to “generously” or “liberally” apply your sunscreen, which can mean different things to different people. A good rule of thumb, according to the AAD, is to use one ounce of sunscreen (enough to fill a shot glass) each application, though you may need more or less depending on your size. It can be tough to gauge how much of a spray sunscreen you’ve