We can’t help it—alongside bikinis, sandals, and abbreviated Fridays—sunscreen feels completely synonymous with summer. (Especially when it smells like banana, pineapple, coconut, or a nostalgic melting pot of all three.) Alas, even though we’re extra diligent about our application (and re-application) during the sunnier, steamier months of the year, our SPF regimen is just as important in the fall and winter. In fact, not wearing sunscreen all-day, everyday—despite the weather or season—is one of the biggest skincare mistakes you can possibly make, according to every dermatologist and facialist I’ve ever talked to. (That’s not drama, it’s fact!)