When the weather gets cooler, the sun can feel less intense. The days are shorter, the sky is often cloudy, and in Seattle, it can be easy to assume that sunscreen matters less once summer is over.
Your skin does not get that memo.
UV exposure happens year-round, and some of the UV rays that have the greatest impact on premature aging, hyperpigmentation, and inflammation are present even when the sun does not feel strong.
UVA and UVB do different things
UVA and UVB are both types of ultraviolet radiation, but they affect the skin differently.
UVB is the primary cause of sunburn. It is strongest during the middle of the day and is more intense during the summer months. UVB plays a major role in the development of skin cancer and can directly damage the DNA within skin cells.
UVA penetrates deeper into the skin and is much more consistent throughout the year. It can pass through clouds and glass, which means your skin can still be exposed while you're driving, sitting near a window, walking around on an overcast day, or spending time outside in the colder months. UVA is also closely associated with photoaging. Repeated exposure contributes to collagen and elastin breakdown, pigmentation changes, uneven skin tone, and the gradual changes we associate with premature aging.
This is why SPF should not be thought of as something you only need when you're trying to avoid a sunburn.
Cloudy does not mean UV-free
One of the biggest misconceptions about fall and winter skincare is that cloudy weather eliminates the need for sunscreen. It doesn't.
Clouds can reduce some UV exposure, but they do not completely block it. UVA in particular can continue to reach your skin throughout the day.
This matters even more if you are working on pigmentation, acne marks, melasma, or an uneven complexion. Your skin can be doing everything right at home, while daily UV exposure continues to stimulate pigment and inflammation.
For skin that is prone to discoloration, consistency matters more than how sunny the day looks.
SPF + Mountains
If you're heading to the mountains this winter, sunscreen becomes even more important.
Fresh snow can reflect a significant amount of UV radiation back toward your skin, increasing your overall exposure. You're not only receiving UV directly from the sky. Light reflected from the ground can reach areas that are easy to overlook, including the underside of your chin, the sides of your face, and your lips. Higher elevations add another factor because UV exposure increases with altitude. A winter day on the mountain can therefore result in substantial UV exposure even when the temperature is freezing.
That is why skiing, snowboarding, winter hiking, and other outdoor activities deserve the same attention to sun protection as a beach day.
Winter skin is already dealing with enough
Cold weather, wind, indoor heating, and lower humidity can all contribute to a compromised skin barrier and increased dryness. UV exposure adds another source of stress.
When the skin is repeatedly exposed to environmental stressors, inflammation can increase and the barrier may have a harder time maintaining its normal function. For some people, this can show up as increased sensitivity, redness, dryness, or a complexion that simply looks more reactive.
Protecting your skin from UV radiation is one way to reduce the cumulative environmental stress your skin experiences throughout the year.
SPF is also part of your pigmentation routine
If you're investing in treatments or products to improve hyperpigmentation, SPF is one of the most important things you can do to protect that progress. UV exposure can stimulate melanin production and contribute to the persistence of discoloration. This is especially important after treatments that intentionally stimulate the skin, when your skin may be more vulnerable to inflammation and pigment changes.
You can spend months improving uneven pigmentation, but inconsistent sun protection can continue to work against those results.
This is why sunscreen isn't just about preventing future damage. It supports the work you're already doing to improve your skin.
Think beyond aging
When people talk about sunscreen, the conversation often centers around wrinkles. But protecting your skin from UV radiation is about much more than that.
Consistent sun protection helps reduce cumulative UV damage associated with:
• Premature collagen breakdown
• Uneven pigmentation
• Persistent hyperpigmentation
• Inflammation and oxidative stress
• Loss of skin elasticity
• Visible photoaging
• Skin cancer
And unlike many skincare products, sunscreen is preventative. It helps protect your skin before that damage becomes something you are trying to correct.
Your fall and winter SPF routine
You don't necessarily need to completely change your sunscreen routine when summer ends. You still want a broad-spectrum SPF that protects against both UVA and UVB. Apply it as the final step of your morning skincare routine and pay attention to areas that are often forgotten, including the ears, neck, chest, and hands.
If you are spending significant time outdoors, skiing, hiking, or exercising outside, reapplication becomes especially important. And remember that sunscreen is not reserved for blue-sky days.
If you can see during the day, UV exposure is part of the environment your skin is navigating.
Fall and winter are actually a great time to become more consistent with SPF. Your skin may not be asking for it as loudly as it does after a summer beach day, but the cumulative protection you give it now matters years from now.
At Sada, we think about skin health as the long game. Protecting your skin every season gives it a better chance to maintain its barrier, tone, texture, and resilience over time.