UV levels are affected by several different factors, this means that UV levels are higher in some parts of NSW than in others – even on the same day.
Geographic location
In regions closer to the equator the sun is higher in the sky. The sun’s rays have a more direct pathway to earth (straight down, not angled) and pass through less atmosphere which acts to absorb UV radiation. For example, all areas north of Sydney need to use sun protection all year round to protect their skin.
Altitude
In higher altitudes (i.e. in the mountains) the air is cleaner and the thinner, and atmosphere absorbs less UV radiation. UV levels increase by 10%-12% with every 1000 metres increase in altitude.
Time of year or season
The angle of the sun varies depending on the time of year. UV radiation is greatest in summer as the sun is high in the sky and its rays pass through less atmosphere before reaching the earth’s surface. In winter, the sun is lower in the sky and its rays have a longer course through the atmosphere; more UV radiation is absorbed, and UV levels are lower.
Time of day
UV radiation levels are lower in the morning, peaking in the middle part of the day (when the sun is overhead) and gradually dropping again throughout the afternoon as the sun moves lower in the sky.
Cloud cover
Thick cloud provides a good filter for UV radiation. Thin and scattered cloud does little to reduce UV levels. Always check your daily local UV levels, as UV can be 3 or above on cool or cloudy days
Reflection
Surfaces such as snow, water and sand reflect UV radiation. Snow reflects between 50 and 88% of UV radiation, sea surf (white foam) reflects 25 to 30% and dry beach sand reflects 15 to 18%. This means that UV radiation reaches you directly and indirectly (when it is scattered and reflected by the snow). Read more about sun protection at the snow.
Artificial UV radiation
UV radiation is available from artificial sources such as solaria (solariums, sun lamps, tanning booths). Research has shown that people who use solariums before the age of 35 increase their risk of developing melanoma by 59%. Commercial solariums were banned in NSW in 2014.
There are many different factors that affect UV levels – even on the same day, UV levels can be higher in some parts of NSW than in others. Remember to check the SunSmart App daily for your local sun protection times – when UV is 3 or above sun protection is needed.
Remember, always use more than one form of sun protection. Never rely on just one.
Read more about when sun protection is required in your local area or check your local sun protection times.
FAQs
The most important factor affecting the level of solar UVR at the earth's surface is the height of the sun in the sky. The higher the sun is in the sky, the shorter the path the UVR has to travel through the atmosphere, so less is absorbed resulting in higher levels of UVR at the surface.
What are the factors affecting UV radiation levels? ›
The UV level is affected by a number of factors including the time of day, time of year, cloud cover, altitude, proximity to the equator, scattering and reflection.
What are 3 things that might affect the amount of UV radiation reaching a certain location on Earth? ›
Surfaces such as snow, water and sand reflect UV radiation. Snow reflects between 50 and 88% of UV radiation, sea surf (white foam) reflects 25 to 30% and dry beach sand reflects 15 to 18%. This means that UV radiation reaches you directly and indirectly (when it is scattered and reflected by the snow).
What are the factors affecting solar UV rays? ›
The amount and intensity of solar radiation that a location or body of water receives depends on a variety of factors. These factors include latitude, season, time of day, cloud cover and altitude. Not all radiation emitted from the sun reaches Earth's surface.
What does UV radiation affect? ›
UV rays, either from the sun or from artificial sources like tanning beds, can cause sunburn. Exposure to UV rays can cause premature aging of the skin and signs of sun damage such as wrinkles, leathery skin, liver spots, actinic keratosis, and solar elastosis. UV rays can also cause eye problems.
What are the factors affecting the position and intensity of UV? ›
The position and intensity is greatly affected by the polarity of solvent. The temperature, concentration and pH of the sample solution affect the position and shape of UV-Vis absorption bands.
What are the 3 factors that caused the changes in solar radiation? ›
Changes in the amount of solar energy input to the total Earth system are caused by three main mechanisms: i) geometric factors related to the Earth's inclination and orbit around the Sun (which alter the distribution of radiation incident on the Earth), ii) processes in the Earth system itself (which regulate the ...
What are 4 factors that affect solar radiation distribution on Earth? ›
The amount of solar radiation that reaches any one spot on the Earth's surface varies according to:
- Geographic location.
- Time of day.
- Season.
- Local landscape.
- Local weather.
The depletion of the ozone layer leads, on the average, to an increase in ground-level ultraviolet radiation, because ozone is an effective absorber of ultraviolet radiation.
What are 5 effects of UV rays? ›
Health Effects of UV Radiation
- Skin cancer.
- Premature aging and other skin damage.
- Cataracts and other eye damage.
- Immune system suppression.
For most individuals, the main source of exposure to ultraviolet (UV) radiation is the sun. Nevertheless, some individuals are exposed to high doses of UV through artificial sources. Sunbeds and sunlamps used for tanning purposes are the main source of deliberate exposure to artificial UV radiation.
When are UV rays strongest? ›
Time of day: UV rays are strongest in the middle of the day, between 10 am and 4 pm. Season of the year: UV rays are stronger during spring and summer months.
What are the factors affecting solar energy? ›
Tilt, orientation, latitude, and climate can have major impacts on a solar system's performance so if you are planning to offset your electric bill with solar it is important to understand how these factors can impact solar production.
What is most affected by the sun's ultraviolet rays? ›
While UVA and UVB rays differ in how they affect the skin, they both do harm. Unprotected exposure to UVA and UVB damages the DNA in skin cells, producing genetic defects, or mutations, that can lead to skin cancer and premature aging. UV rays can also cause eye damage, including cataracts and eyelid cancers.
Does UV affect solar? ›
Photons from infrared light don't have enough energy to knock electrons off and create electrical flow. And photons from ultraviolet light have too much energy—they can still create electrical flow, but a lot of energy is wasted as heat. This heat warms the panels, which decreases their efficiency.
