Sun Protection 101: Building a Routine That Actually Works
May is Skin Cancer Awareness Month, and at Dermatology of North Asheville, there is no topic we feel more strongly about than sun protection. Skin cancer is the most common cancer in the United States — but it is also one of the most preventable. The key is building a sun protection routine that you will actually follow, day in and day out.
We see patients every week who are surprised to learn that their sunscreen habits, while well-intentioned, have gaps. Maybe they are using the wrong SPF, skipping reapplication, or not protecting the spots that matter most. This guide is designed to change that.
Understanding SPF
SPF, or Sun Protection Factor, measures how well a sunscreen protects against UVB rays — the rays primarily responsible for sunburn and a significant contributor to skin cancer risk. Here is a simple way to think about it:
SPF 15 blocks about 93% of UVB rays
SPF 30 blocks about 97% of UVB rays
SPF 50 blocks about 98% of UVB rays
The American Academy of Dermatology recommends using a broad-spectrum sunscreen with an SPF of 30 or higher for daily use. For extended outdoor time — hiking the trails around Asheville, gardening, or spending a day at the lake — SPF 50 or higher is a smart choice.
No sunscreen blocks 100% of UV rays, which is why sunscreen is one layer of protection, not the only layer.
Broad-Spectrum: Why It Matters
When shopping for sunscreen, the words "broad-spectrum" on the label are non-negotiable. Here is why:
The sun emits two types of ultraviolet radiation that affect the skin: UVA and UVB. UVB rays cause sunburn and play a key role in developing skin cancer. UVA rays penetrate more deeply into the skin and are the primary driver of premature aging — think fine lines, sunspots, and loss of elasticity. UVA rays are also present year-round and can pass through clouds and glass.
A broad-spectrum sunscreen protects against both. If your sunscreen label does not say "broad-spectrum," it is only addressing part of the problem.
How Much Sunscreen Are You Actually Using?
Most people apply far less sunscreen than they need for the SPF on the label to be effective. Dermatologists recommend:
One ounce (roughly a shot glass full) to cover the exposed skin of the average adult body
A nickel-sized amount for the face alone
Applying too little is one of the most common sun protection mistakes we see. If you are going through a bottle of SPF 50 very slowly, there is a good chance you are not applying enough.
Reapplication: The Step Most People Skip
Sunscreen is not a one-and-done application. It breaks down over time, especially with sun exposure, sweating, and water. The guidelines are straightforward:
Reapply every two hours when outdoors
Reapply immediately after swimming or heavy sweating, regardless of whether the label says "water resistant"
Apply sunscreen 15 to 30 minutes before going outside to allow it to bind to the skin
Water-resistant formulas are helpful, but no sunscreen is waterproof. That label simply means the SPF holds up for 40 to 80 minutes in water — after that, reapplication is essential.
The Spots People Miss
Even diligent sunscreen users tend to miss certain areas. Pay close attention to:
Ears — one of the most common sites for skin cancer, and almost always overlooked
Scalp and part line — especially important for those with thinning hair; a spray sunscreen or hat offers protection here
Back of the neck
Tops of the feet — often exposed in sandals
Lips — use an SPF lip balm
Back of the hands — these age visibly and are frequently sun-exposed while driving
Beyond Sunscreen: The Layers of Sun Protection
Sunscreen is essential, but a truly effective sun protection routine goes beyond a bottle. Dermatologists recommend a layered approach:
Seek shade. The sun's UV rays are strongest between 10 a.m. and 4 p.m. Planning outdoor activities for early morning or late afternoon significantly reduces exposure.
Wear protective clothing. Standard clothing varies widely in UV protection. A white cotton T-shirt offers only about UPF 5 to 7 — far less than most people assume. UPF-rated sun-protective clothing is specifically engineered to block UV radiation. At Dermatology of North Asheville, we carry an in-office selection of Coolibar UPF 50+ clothing, including styles suited for everything from everyday errands to outdoor adventures. It is one of the simplest and most reliable ways to protect the skin you cannot easily reach with sunscreen.
Wear sunglasses. UV exposure contributes to cataracts and can affect the delicate skin around the eyes. Look for sunglasses labeled UV400 or 100% UV protection.
Wear a wide-brimmed hat. A hat with a brim of at least three inches shades the face, ears, and back of the neck — all high-risk areas.
Choosing the Right Sunscreen Formula for You
The best sunscreen is the one you will actually use consistently. There are two main types:
Chemical sunscreens absorb UV radiation and convert it to heat. These tend to be lighter and easier to blend into the skin, making them popular for daily facial use.
Mineral sunscreens (containing zinc oxide or titanium dioxide) sit on top of the skin and physically deflect UV rays. They are generally recommended for sensitive skin, children, and patients who have had skin cancer or are undergoing certain treatments.
Both types are effective when used correctly. If you are unsure which is right for you, our team is happy to help you find a formulation that works for your skin type.
Sun Protection Is a Year-Round Commitment
One of the most common misconceptions we encounter is that sun protection only matters in summer. In reality, UVA rays are present and damaging every day of the year, regardless of the season or cloud cover. Up to 80% of UV rays can penetrate cloud cover, and at higher elevations — like here in the Asheville area — UV intensity increases meaningfully.
Daily sunscreen use, even on overcast days and during the winter months, is one of the most impactful habits you can build for your long-term skin health.
When to See a Dermatologist
Sun protection is your best defense against skin cancer, but regular professional skin exams are equally important. Annual full-body skin checks allow a dermatologist to identify suspicious lesions that may be difficult to see on your own, particularly on the scalp, back, and other hard-to-reach areas.
If you notice a new or changing spot — one that is asymmetrical, has irregular borders, contains multiple colors, is larger than a pencil eraser, or has changed over time — do not wait for your annual exam. Schedule an appointment promptly.
