Just a reminder really. I’ll (try to!) make it short.
First of all, wear sunscreen EVERY DAY, regardless of the weather or whether you need to be outdoor for a long time. If you can see any daylight, UV rays are present and you need to use protection. I know it means you have to wear sunscreen every day for the rest of our lives, but it is human beings’ fault in the first place to have ruined Nature’s ability to shield UV rays. So we have only ourselves to blame.
Secondly, apart from proper UVB protection, which the SPF represents, UVA protection is equally important. UVB rays burn our skin and both UVA and UVB rays cause skin cancer as well as accelerate the aging of the skin (by damaging collagen fibers).
Thirdly, a sunscreen with proper UVA protection should have at least one of the following five ingredients:
avobenzone (aka Parsol 1789 or butyl methoxydibenzoylmethane)
(from Paula Begoun’s website, and go there for a very comprehensive guide on sun protection)
Do learn to check the ingredient list of the sunscreen product (or any skincare product, actually) you buy. If a sunscreen product does not have any of those ingredients, it is NOT something you should pay any money for.