The smell of sunscreen was once the signal that summer had officially arrived. It meant days by the pool, beach trips, and endless sunshine. But now, it’s become a non-negotiable part of daily skincare—it’s an essential part of protecting your skin every single day, no matter the season.  If using sunscreen every day isn’t already a habit, but you care about keeping your skin healthy and avoiding long-term damage, this is the reminder you’ve been waiting for. Keep reading to learn why sunscreen matters year-round and how to start making it a habit.

Sunscreen: The Bases 

Ultraviolet (UV) light is not visible to the human eye because its wavelengths are shorter than the light we can see. Within the UV spectrum, two types of rays—UVA and UVB—can harm your skin and increase the risk of skin cancer. A quick way to remember the difference: UVA ages, and UVB burns.

UVB rays are the primary cause of sunburn and play a major role in developing skin cancer. The SPF (sun protection factor) number on sunscreen mainly indicates how well it protects against UVB rays.

UVA rays penetrate deeper into the skin, contributing to wrinkles, fine lines, and dark spots. While both UVA and UVB rays can cause sunburn and aging, UVA is more associated with long-term damage, while UVB is more likely to lead to sunburn and skin cancer.

To stay protected, always choose a sunscreen labeled “broad-spectrum.” This ensures that the product’s ingredients shield you from both UVA and UVB rays, offering full protection for your skin.

There’s no simple answer or universal guide to sun protection, but understanding these basics will help you make smarter choices for your skin’s health.

Does a Sunscreen With a High SPF Protect Skin Better Than One With a Lower SPF? And How High Should You Go? 

Before you head out into the sun, you might want to double up on your sunscreen. A recent study published in Acta Dermato-Venereology reveals that most people apply sunscreen too thinly to get the full protection listed on the label. 

Manufacturers determine SPF levels based on applying sunscreen at a thickness of 2mg/cm², but the typical quick and thin application only delivers about 40% of the expected UV protection. The research found that when sunscreen was applied too lightly, the skin suffered much DNA damage after just five days of UV exposure. In contrast, when used properly, sunscreen significantly reduces damage—even over multiple days—compared to skin with no sunscreen exposed for just a single day.

There’s no doubt sunscreen is essential for protecting against the harmful effects of UV rays. The study author Antony Young, a professor from King’s College London explained the way sunscreen is applied affects how well it works. Since most people don’t use it as intended, it’s safer to choose a higher SPF than you think you need.

The takeaway? Sunscreen works—if you use enough. For maximum protection, aim for a thicker layer than you might think is necessary and reapply regularly, especially on long days in the sun.h

What Does the SPF Number Mean?

The SPF number on sunscreen tells you how long it would take for UV rays to redden your skin when applied correctly, compared to going without it. For example, SPF 30 means it would take 30 times longer to burn than without sunscreen. SPF 30 blocks about 97% of UVB rays, while SPF 50 blocks about 98%. That small difference might not seem important, but SPF 30 allows 50% more UV rays through than SPF 50, increasing the risk of damage.

In a lab, sunscreens with higher SPF offer better protection from sunburn, DNA damage, and UVA exposure. But real life isn’t a controlled environment. High-SPF sunscreens can give people a false sense of security. This leads to spending more time in the sun, skipping reapplication, or neglecting other protective measures like seeking shade or wearing a hat. As a result, they might end up with more UV damage than expected.

For those with high skin cancer risks, genetic conditions like albinism, or who are exposed to intense UV rays—such as during skiing, hiking at high altitudes, or vacations near the equator—SPF 50 or higher may still be necessary.

The Skin Cancer Foundation recommends using a water-resistant, broad-spectrum sunscreen with at least SPF 30 for extended outdoor activities. No matter the SPF, apply one ounce (two tablespoons) 30 minutes before going outside and reapply every two hours or immediately after swimming or sweating.

Know that higher SPF can help, but only if applied correctly and combined with other sun-safe practices.

Aiming for the Best Overall Strategy to protect Your Skin

Experts recommend using SPF between 30 and 50, this range offers strong protection without giving a false sense of total safety that can come with higher SPFs. But sunscreen alone isn’t enough. No single method can fully protect you from UV damage. 

For the best defense against the sun, sunscreen should be part of your strategy. Along with applying sunscreen, the American Cancer Society suggests wearing protective clothing, including wide-brimmed hats and UV-blocking sunglasses. Seek shade when possible, especially between 10 a.m. and 4 p.m., when the sun’s rays are strongest. Finally, skip tanning beds, which can cause long-term skin damage and increase your risk of skin cancer. Sunscreen is an essential tool, but it works best as part of a broader strategy. Layering these protective measures is what helps you keep your skin healthy and reduce your risk of sun-related damage.