A mild sunburn typically heals in 3 to 7 days. A more severe sunburn with blisters can take several weeks. The exact timeline depends on how deeply the UV radiation penetrated your skin and how you care for the burn during recovery.
Mild Sunburn: 3 to 7 Days
A first-degree sunburn damages only the outer layer of skin. It turns red, feels warm and tender, and may sting when you touch it or take a shower. This is the most common type of sunburn, and it resolves on its own without medical treatment. Redness and pain usually peak around 24 to 36 hours after sun exposure, then gradually fade over the next few days.
Peeling typically starts about three days after you get burned. This is your body shedding damaged cells to make way for healthy skin underneath. Once peeling begins, it usually continues until the burn has fully healed, roughly seven days for a mild to moderate burn. Resist the urge to peel or pick at flaking skin, as pulling it off prematurely can expose raw skin beneath and slow the process down.
Blistering Sunburn: 2 to 3 Weeks
A second-degree sunburn goes deeper, damaging the middle layer of skin. Blisters form because fluid collects between the damaged layers. This type of burn is significantly more painful, and healing takes weeks rather than days. Blisters should be left intact. They act as a natural bandage, protecting the raw skin underneath from infection.
Blistering sunburns also carry a higher risk of complications. Damaged skin loses its ability to hold in moisture effectively, which can lead to dehydration. You may also develop systemic symptoms: fever, chills, headache, nausea, or vomiting. These signs indicate your body is mounting a significant inflammatory response. Bright red or oozing skin, severe pain, or feeling extremely cold and shivering all warrant a call to your doctor.
What Happens Inside Your Skin
UV radiation directly damages the DNA in your skin cells. Your body has repair machinery that identifies and fixes this damage, but the process takes time. In the hours after a burn, your immune system floods the area with blood and inflammatory signals, which is what produces the redness, swelling, and heat you feel. Cells too damaged to repair themselves are tagged for removal, which is ultimately what causes peeling days later.
Interestingly, skin that has been gradually exposed to sun over time appears to repair DNA damage faster than untanned skin, suggesting that UV exposure activates the body’s repair systems. This doesn’t mean a tan protects you from burns, but it does help explain why people who rarely see the sun tend to burn more severely.
How to Speed Up Healing
You can’t undo UV damage once it’s happened, but the right care in the first 24 to 48 hours makes a real difference in how quickly you recover and how much discomfort you experience along the way.
Cool the skin early. Apply a clean towel dampened with cool tap water to the burned area, or take a cool bath. Adding about 2 ounces of baking soda to the tub can help soothe irritation. Aim for about 10 minutes of cooling, several times a day. Avoid ice or ice-cold water directly on the burn, which can further irritate damaged skin.
Take a pain reliever promptly. Ibuprofen or acetaminophen taken as soon as possible after sun exposure helps reduce pain and inflammation. Ibuprofen in particular targets the inflammatory response driving much of the redness and swelling.
Moisturize consistently. Aloe vera gel or calamine lotion applied to the burn helps the skin retain moisture and reduces tightness as it heals. Refrigerating the product before applying adds an extra cooling effect. Avoid petroleum-based products or anything with heavy fragrances, which can trap heat or irritate raw skin.
Drink extra fluids. Sunburns draw fluid to the skin’s surface and away from the rest of the body, making dehydration a genuine concern even with mild burns. Start drinking extra water and electrolyte-containing beverages as soon as you notice the burn. This is one of the most overlooked steps in recovery, and it supports healing from the inside out.
What Not to Do While Healing
Avoid further sun exposure on the burned area until it has fully healed. New skin underneath a peeling burn is especially vulnerable to UV damage. If you have to go outside, cover the area with loose clothing rather than relying on sunscreen alone, since applying sunscreen to tender or peeling skin can be painful and less effective.
Don’t pop blisters. The fluid inside them cushions the damaged tissue and reduces infection risk. If a blister breaks on its own, gently clean the area and apply a light bandage. Avoid hot showers, harsh soaps, and exfoliating products until the burn has resolved. All of these strip moisture from already compromised skin and extend healing time.
The Long-Term Stakes
Even after the redness fades and your skin looks normal again, UV damage has a cumulative effect on your skin cancer risk. A meta-analysis published in the Journal of Cancer Research and Therapeutics found that experiencing a sunburn at any point in life increases basal cell carcinoma risk by about 40%. The numbers climb steeply with repeated burns: five sunburns per decade in adulthood more than doubles the risk.
Childhood sunburns are particularly consequential. Five burns per decade during childhood increase basal cell carcinoma risk by 1.86 times. This is because younger skin cells divide more rapidly, giving damaged DNA more opportunities to replicate errors that can eventually become cancerous. A single blistering sunburn in childhood or adolescence also roughly doubles the lifetime risk of melanoma, the most dangerous form of skin cancer. These statistics make prevention far more valuable than any treatment after the fact.