You need sunshine to get a tan. As most people do, I have always associated tanning with sunny weather. However, the UV rays that darken your skin can penetrate through almost any weather conditions.
So, can you tan through clouds or do you need to wait for sunny skies? The simple answer is that you can tan whether the sun is shining or full of clouds but there is more to consider.
You Can Still Get Burned on a Cloudy Day
The bright sunshine does not burn your skin or give you a tan. You can thank the ultraviolet (UV) rays that the sun emits for your sunburn or tan.
These UV rays still penetrate your skin even when the sky is cloudy. However, the clouds do offer a small amount of protection against the UV radiation. This means that it may take longer to burn or tan on an overcast day.
Understanding the Tanning Process
While it may take longer to tan or burn on a cloudy day, I do not want to risk spending too much time exposed to UV radiation. To understand the effects of the clouds on tanning, I needed to know how the tanning process works.
A natural pigment found in your body called melanin is responsible for the color of your skin. People with darker skin have more melanin while those with lighter skin have less melanin. Melanin is produced naturally and as a defense mechanism when your skin is damaged. It offers protection against UV radiation.
By exposing your body to UV rays, the radiation and DNA damage causes your body to produce more melanin to repair the damage. At the same time, your existing melanin can darken. These processes result in the temporarily darker skin.
The Effects of UVA and UVB Radiation
The darkening of the skin is caused by exposure to UV rays. However, there are two types of UV rays and each one has a different effect on the skin.
The UVA rays reach deeper into the skin and are the primary cause of tanning and sunburns. When your body is exposed to UVA rays, the UV radiation causes oxidative stress, which causes the existing melanin in your skin to darken. It also redistributes the melanin, which also helps to create an even tan.
While UVA rays can darken your skin temporarily, they do not change the production of melanin. You do not gain more of this pigment or receive any additional protection against getting burned.
UVB rays primarily affect the outer layers of the skin. Unlike UVA rays, UVB rays can cause your body to produce more melanin. However, this increased production occurs gradually and may not be noticeable until several days later.
Indirect and Direct DNA Damage to Your Skin
UVA and UVB rays cause different types of damage to your skin, resulting in different types of tanning and burning. With UVA rays, you receive indirect DNA damage as the UVA radiation creates oxidative stress that leads to the darkening of existing melanin.
The UVB rays cause direct DNA damage, resulting in more melanin production and increasing your risk of sunburn. When you get a sunburn, it is most likely the UVB rays that are causing most of the damage. However, the increased production of melanin caused by UVB rays provides a longer-lasting tan.
How Much UV Radiation Gets Blocked by Clouds?
The clouds do not always block the UV radiation. In fact, some clouds can increase UV radiation.
When the clouds are grey and heavy, about two-thirds of the UVA and UVB rays can get blocked. With most of the UV rays blocked, the risk of burning or tanning is reduced.
When the sun breaks through the clouds or the clouds are scattered, up to 89% of the UV rays can still penetrate your skin. However, if the clouds are puffy and white, you may receive even more UV exposure. The white, puffy clouds can deflect the UV rays, increasing the total amount of UV radiation that reaches the surface.
Check Your Local UV Index for Tanning Conditions
Instead of focusing on the condition of the sky, you should consider checking your local UV index.
The UV index was created by the National Weather Service and the United States Environmental Protection Agency. It gives the public a general guide for determining the threat of UV radiation on a given day.
A low UV index of 1 or 2 means that you can expect minimal UV exposure when outdoors. 3 to 5 on the UV index indicates moderate exposure. You should still wear sunscreen when the UV index lists moderate exposure.
If the UV index is 6 or higher, everyone should wear protection against sunburn. This is when you are most likely to get burned if you spend too much time outdoors.
How Can You Tan Through Clouds Without Burning?
When the skies are full of fluffy white clouds, you may receive more UV exposure compared to a clear day. On cloudy days, you may not worry as much about your sun exposure. However, you can still get burned if you stay outside for too long.
If you want to try to tan on a cloudy day, you should follow the same precautions that you use when sunbathing on a sunny day. You should apply suntan lotion evenly over all exposed areas of skin. You should also avoid laying outside for too long and reapply the lotion every couple of hours.
Conclusion: Clouds Do Not Block the UV Rays
The bottom line is that you do not need to wait for a sunny day to tan. You may even tan faster when the sky has a lot of white, puffy clouds.
The only time when you may receive less UV exposure during the day is when the sky is completely grey. This creates more cover against the UV radiation, blocking up to 66% of the UV rays.
If you want to tan outdoors, the clouds may not make much of a difference unless the sky is covered in grey clouds. Whether the sky is clear or cloudy, I suggest that you always wear sun protection when you plan on spending time outdoors even when you are not tanning.