In my post why you want sun-protective clothing for a great look, I already explained that ultraviolet (UV) radiation is the harmful part of the solar spectrum. The post below explains why the rule “short shadow, seek shade” fails to protect you fully from harmful UV rays and points out measures that you can do reduce Sun exposure.
- Which Factors Determine Your Exposure to UV Radiation
- How to Reduce Sun exposure
- Avoid the Sun at Its Zenith
- Be Aware of Your Total Daily Exposure
- Hike at Low Elevation
- Be Aware that Diffuse UV Radiation also Exists in the Shadow
- Prefer Cloudy over Cloud-Free for Being Outside
- Don’t Harm the Ozone Layer
- Be Aware that More UV Reaches the Ground in Pristine Air
- Wear Sun-Protective Clothing and Sunscreen
- Best Brand for Affordable Sun-Protective Clothes
- Where to Buy Inexpensive Sun-Protective Attire
Updated: 1/18/2022
Disclosure: Ad. The Women’s Panorama Dress UPF 50+ is a sample from Coolibar’s women dress collection. The post is not endorsed by them. I wrote it entirely myself and it represents my own 100% honest opinion.
Which Factors Determine Your Exposure to UV Radiation
There are at least ten factors that affect your exposure to solar UV radiation namely time spend in the Sun, solar zenith or elevation angle, your altitude and location on Earth, the season, reflection from surfaces, the ozone layer, atmospheric trace gases, water vapor and atmospheric particles including pollutants, cloud ice crystals and water droplets, using sunscreen and what you wear.

How to Reduce Your Sun Exposure
While you cannot do anything about the physics, you can easily use what the physics does to work in your favor.
Avoid the Sun at Its Zenith
The solar zenith angle gives the angle between the Sun at local noon (when sun radiation is the most powerful) and the center of the Sun. The solar elevation gives the angle of the Sun above the horizon and the Sun. They refer to the Sun’s position in the sky.
In plain English, the higher the star in the sky, the shorter is the distance the UV radiation travels thru the atmosphere, and the more UV can reach you. Consequently,
Reduce the time that you spend outside around local noon. #sunsafe #skinhealth Click To TweetTake your walk, run or shop early in the morning or evening.
Be Aware of Your Total Daily Exposure
The strength differs also with season, latitude and hemisphere. It is strongest around summer solstice and lowest around winter solstice. Due to the angle of the Earth to the ecliptic the northern and southern hemisphere have different exposure to the solar radiation. The southern hemisphere receives more than the northern hemisphere. In the respective summer, the Polar regions receive solar radiation 24/7. This means summed up over a day these areas experience more solar input at the top of the atmosphere than the Tropics on that same day. Reduce the time spend outside.

Don't let the Arctic fool you. #triva #funfacts Click To Tweet
Hike at Low Elevation
The importance of the distance the rays have to travel thru the atmosphere also means that altitude plays a role. You experience more exposure at local noon and same latitude, when you are hiking on a mountain (i.e. at high elevation) than in a place just around sea level height. Consequently, ask yourself whether the great view from that mountain is really worth it? If not, hike in the valley or at lower altitude.
Be Aware that Diffuse UV Radiation Also Exists in the Shadow
Albedo refers to the ratio of the reflected sunlight of a given wavelength to the sunlight received at that wavelength. Let’s put this physical effect in easy words what this means for your exposure. When you are on a glacier, on snow or ice, close to the water, a mirror or any other reflective surface, you not only receive the Sun rays that directly come from the Sun, but also some of those where reflected from other surfaces. This reflection can reach areas that are shaded. As a result, following the general rule of thumb
Watch your shadow. Short shadow, seek shade. #Sunprotection #skinhealth Click To Tweetonly means that you reduce your exposure! The so called diffuse UV radiation is the reason why being in the shade fails to rescue you from sunburn.
Prefer Cloudy over Cloud-free for Being Outside
Cloudiness. You have made yourself the experience that clouds with their ice crystals and/or water droplets dim down the Sunlight at the ground. The thicker the clouds, and the more the sky is covered the larger the effect. Cloud layers at different heights also influence the solar radiation. Note that sunlight can also be reflected between clouds in all directions.
Don’t Harm the Ozone Layer
The ozone concentration around 30-35 km height is critical. The ozone layer absorbs on average about 98% of the UV radiation in the wavelength range of 200 nm to 315 nm. Absorption is slightly lower (higher) when there is less (more) ozone.

In the ozone layer, freons, i.e., gases used in spray bottles, destroy ozone. Therefore, only use pump sprays.
Be Aware that More UV Reaches the Ground in Pristine Air
Other gases and aerosols. Ozone is not the only gas that absorbs radiation in the UV range. Water vapor, carbon dioxide (CO2), as well as some aerosols can absorb UV light at different heights. As a result, their vertical profiles of concentration and horizontal distribution can influence the exposure. This means that you are more in “danger” of a sunburn in a National Park or Wilderness Area than in a mega city.


Wear Sun-Protective Clothing and Apply Sunscreen
While you only have limited control with the above points, you are fully in control of what you wear. When you want to protect your skin
Not all clothes are equal. Wear sun-protective clothes. #skinhealth #Coolibar Click To Tweet.
Wearing Sun-safe clothing and applying sunscreen to uncovered skin is your best measure of protection.
Make wearing sun-protective clothes and sunscreen a habit. #health #selfcare Click To Tweet

Best Brand for Affordable Sun-Protective Clothes
Coolibar produces very chic sun-protective clothing. The look of the day, for example, features their Women’s Panorama Dress with UPF 50+. You can learn more about UPF 50+ in my Coolibar review post at the link.

The fabric feels super soft. The dress is well sewn, i.e. the stripes match at the seams. It comes also in black with white stripes and white with black stripes in sizes XXS to 3X for $99. Thus, every woman can afford to protect herself, look chic and feel comfortable at the same time.
You owe yourself to feel safe, comfortable and chic. #health #agelessstyle Click To TweetI am wearing a size S and it is a perfect fit.

Where to Buy Inexpensive Sun-Protective Attire
Their collection encompasses everything from vacation swimwear and beach cover ups including hats over outdoor clothing to business casual attire. Browse their collection now to convince and protect yourself.
Reduce your risk of skin cancer, wear sun-protective clothes. #skinhealth #Coolibar Click To Tweet
References
Mölders, N., Kramm, G., 2014. Lectures in Meteorology, Springer, Heidelberg.
Mölders, N. and Kramm, G., 2018. Climatology of Air Quality in Arctic Cities—Inventory and Assessment. Open Journal of Air Pollution, 7, 48-93. doi: 10.4236/ojap.2018.71004.
Photos of me: G. Kramm
© 2013-2022 Nicole Mölders | All rights reserved
Yes, it’s crazy sunny here in beautiful Australia all year round and of course that ozone layer damage down here too… cute dress, Nicole!! I love your incredible scientific knowledge – always learning something here!
Have a great week!
Donna 🧚🏻♀️❤️🐝
Schönes Outfit liebe Nicole. Meine Devise im Sommer: nicht in die pralle Sonne. Das halte ich nicht lange aus. Ansonsten gut eincremen mit einem hohen Lichtschutzfaktor.
Liebe Grüße Sabine