Wearing sunscreen is recommended to protect your skin from the harmful effects of ultraviolet (UV) radiation, regardless of the temperature outside. UV radiation can be present even on cloudy or cool days, so it's important to use sunscreen whenever you are exposed to sunlight.
The American Academy of Dermatology (AAD) recommends using sunscreen with an SPF (sun protection factor) of 30 or higher every day as part of your sun protection routine. It should be applied to all exposed skin, including your face, neck, arms, and any other areas not covered by clothing.
In general, it's advisable to apply sunscreen about 15 to 30 minutes before going outside, allowing it enough time to absorb into your skin. Reapply sunscreen every two hours, or more frequently if you are sweating or engaging in activities that may cause the sunscreen to wear off.
Remember that UV radiation can penetrate through clouds and windows, so even if you are indoors or the weather seems mild, it's still important to protect your skin from the sun's harmful rays.