Summer's Coming To an End. Can I Stop Wearing SPF Now?

Short answer: no. UVA doesn’t take a season off, so your SPF shouldn’t either.

If there is daylight, there is UV, and the UVA rays that age your skin the most don’t discriminate by season.

Why UVB Fades but UVA Doesn't

UV exposure comes from two rays: UVB and UVA. UVB, the shorter wavelength ray behind sunburns, drops off in the fall and winter as the sun sits lower in the sky. UVA is different. It’s the longer wavelength ray responsible for collagen breakdown, fine lines, and dark spots, and its intensity stays relatively constant year-round.

That distinction matters because UVA is also the ray most likely to catch you off guard. Up to 80% of UV passes right through cloud cover, more than 50% of UVA penetrates standard window glass, and fresh snow reflects over 80% of UV back onto skin – meaning exposure can actually increase in winter. An overcast commute or a sunny afternoon at your desk still counts, even when it doesn’t feel like it.

None of this shows up as a sunburn. It shows up years later, as the fine lines and hyperpigmentation SPF is made to prevent.

Why Retinol and In-Office Treatments Aren’t a Substitute

Fair question: if you’re already using retinol and getting occasional facials and peels, do you still need daily SPF? Yes, those treatments and SPF solve different problems.

Retinol speeds up cell turnover and supports collagen production at the skin’s surface. It can improve the look of photoaging but improving how existing damage looks isn’t the same as stopping new damage from happening. Sun protection prevents photoaging before it starts; retinoids, lasers, chemical peels and microneedling manage damage that’s already there.

UVA keeps reaching deeper layers of skin and breaking down collagen every day you’re unprotected, regardless of what your retinol is doing on the surface. Retinol without SPF is like patching one leak in a boat while another stays wide open.

The Step Your Future Skin Will Thank You For

Wearing SPF through fall and winter is the cheaper, lower-effort choice. Daily SPF means:

• Firmer skin over time, because SPF slows the collagen breakdown UVA drives
• More even tone, since UVA is the main driver of hyperpigmentation
• Calmer skin, with fewer UV-triggered flare-ups and less redness
• Stronger long-term skin health, including lower skin cancer risk
• A routine that prevents rather than corrects

Prevention is almost always less expensive than correction.

How SunDay Makes It an Easy Habit

We all love a self-care routine, but historically SPF wasn’t a fun step to add – formulas felt heavy and greasy, or left a scent behind that just doesn’t belong at the office in November. SONNI’s SunDay system makes broad-spectrum SPF effortless, so protection doesn’t depend on the weather report.

Reach for the Mineral Serum on days you want SPF layered under makeup without residue, or grab Invisible Defense for sun protection and moisturizer in one step. Keep the Body Balm on hand for hands, neck, ears – the spots people forget once the temperature drops.

The winter routine is the same as the summer one: apply in the morning, and reapply if you are outside for more than a couple of hours. Cold weather changes how it feels, not how it works.

TL;DR

UVA doesn’t take a season off, so your SPF shouldn’t either.

Clouds, glass, and snow don’t block UVA the way most people assume – some conditions meaningfully increase exposure. Retinol and in-office treatments improve existing damage; they don’t replace daily UV protection.

Daily SPF is the lower-cost, lower-effort habit – as non-negotiable as your morning coffee or workout.