Detailed answer

Yes, you should use sunscreen on cloudy days. Clouds do not completely block UV rays, and up to 80% of UV radiation can still penetrate through cloud cover. This means that your skin can still be exposed to harmful UV rays, even on a cloudy day. Using sunscreen helps protect your skin from UV damage, which can contribute to premature aging, sunburns, and an increased risk of skin cancer. It is important to apply a broad-spectrum sunscreen with at least SPF 30, even on cloudy days, and reapply every two hours.