I don't skip the spf unless I plan to stay indoors the entire day. I wouldn't reapply though if I'm only outside for an hour. For reference, I use a retinoid which makes my skin more sensitive to sun damage and also I just want to keep my skin decent in middle age.

Edit to say that I change my sunscreens seasonally. In winter, I'm less concerned about the spf rating and my skin is dryer, so I use moisturizers with spf. In summer I go for 50 SPF with the highest UVA rating I can find and make sure it's water resistant.