Cloudy Day? Up to 80% of UV Still Gets Through
Gray skies feel like a free pass to skip SPF — but most of the UV is still reaching your skin.
Up to 80% of the sun's UV rays pass through clouds, so sunburn and cumulative skin damage can occur even on overcast days.
Dermatology guidance notes that because cloud cover lets the majority of UV through, sunscreen is recommended every day the sun is up — not just when the sky looks bright.
Questions we get a lot
Can you really get sunburned on a cloudy day?
Yes. Up to 80% of UV rays pass through clouds, so a gray day still delivers enough UV to burn and to cause cumulative damage. The sky filters visible brightness more than it filters UV, which is why the risk is easy to underestimate. Sunscreen is still worthwhile.
Do I need to wear sunscreen every day?
Dermatology guidance recommends daily sunscreen because UV reaches your skin even when it isn't sunny or hot. Cumulative exposure across ordinary cloudy days adds up over the years. A daily broad-spectrum SPF is a simple way to reduce that running total.
Does clouds blocking the sun mean lower skin cancer risk?
Not as much as people assume. Because up to 80% of UV penetrates cloud cover, overcast days still contribute to the long-term UV dose tied to photoaging and skin cancer. Treating cloudy days as protection-free is a common myth worth dropping.
r/SkincareAddiction: 'It's overcast like 8 months of the year where I live — do I really need SPF on days I never see the sun?'