The ozone layer over New Zealand is thinner. The ozone layer is like the Earth's personal sun protectant. The ozone layer's role is to absorb the harmful UV rays that are sent from the sun.
First, Earth's elliptical orbit means it is closest to the sun in the New Zealand summer months of December and January. Second, New Zealand's relatively clean air means UV radiation is less likely to be scattered by airborne-pollution and more UV radiation reaches the ground.
New Zealand's rather cool and temperate temperatures can easily hide the harmful effects of the sun. Yet in any season and any weather, the New Zealand sun can burn. Many people say they get more sunburned in New Zealand than anywhere else in the world, even Australia!
UV radiation levels are at their peak in New Zealand from September to April, especially between 10am and 4pm. However, UV radiation levels can also be high when you are at high altitudes or around snow or ice. Even mild sunburn can damage your skin and increase your risk of skin cancer.
In terms of energy, the sun is stronger in Australia due to it being closer to the equator. But in terms of UV light which causes sunburn, it is stronger in New Zealand due to a thinner ozone layer, and less pollution (clearer air).
Australia's unusually harsh sunshine results mainly from its location in the Southern Hemisphere. The elliptical orbit of the Earth places the Southern Hemisphere closer to the sun during its summer months than the Northern Hemisphere during its summer.
UV problem of another kind
"Tasmania is unique with the fact that in summer it gets to extreme level, and in winter it doesn't even get to moderate," Mr Carr said.
The sun in New Zealand is much stronger than elsewhere and in warmer months you can get burnt quickly without sunscreen or other sun protection. This is because we have relatively little air pollution compared with many other countries, and less ozone, which makes the UV rays in our sunlight very strong.
All of the two main islands of New Zealand are more than 34 degrees south of the equator. Over 90 % of Australia is north of 34 degrees, that is more than 90% of Australia is closer to the equator than all of New Zealand. The closer to the equator you get, the hotter it gets.
Miles and miles of rolling green hills and paddocks make for scenery that is only matched in parts of Scandinavia or Patagonia. Australia, by contrast, is mainly a desert with some coastal beaches. New Zealand's greenery is produced by some healthy seasonal weather, including a decent winter.
The maximum UVI of 25 is for the grid cell at 13.5° S, 172° W, centred on Cuzco in Peru. The city is at 3360 m a.s.l., with surrounding terrain extending to over 6000 m a.s.l. As the capital of the Inca empire, Cuzco seems to be well sited for sun worship.
The ozone layer over New Zealand is thinner.
Unfortunately, due to decades of man-made gas emissions, the ozone layer over New Zealand has continuously thinned. The ozone layer is like the Earth's personal sun protectant. The ozone layer's role is to absorb the harmful UV rays that are sent from the sun.
Australia is warmer than New Zealand, with a summer average of 30°C and winter average of 15°C. New Zealand, is a touch cooler, with a summer average around 20 to 25 degrees and a winter average around 12°.
New Zealand's size, location, orientation, and dominance by mountains (especially on the South Island), create a very different climatic regime than Australia. Four major physical factors dominate New Zealand's climate.
The climate in New Zealand is maritime, characterized by weather influenced by ocean patterns. On the other hand, Australia has a self-adjusting, continental climate. It is warmer at circa 59 degrees in the winter and circa 86 degrees in the summer. New Zealand goes up to around 77 in the summer and 53 in the winter.
It is possible to get sunburnt in a very short time. When UV radiation levels are high, damage to people with light coloured skin can occur in as little as 12 minutes. Check the Sun Protection Alert, NIWA UV forecasts, and UVNZ app for details about the time each day that you need to protect your skin and eyes.
Which is better Australia or New Zealand, for study? Both countries have become preferred study destinations for international students globally. While New Zealand offers a great work-life balance, Australia's education system adds to its widely recognised academic reputation. Both countries are unique in their ways.
New Zealand is more about mountains, lush rolling hills, forests, lakes and waterfalls, while over in Australia you have bushland, tropical rainforest, ancient stone escarpments and red desert. Both countries have gorgeous coastlines with remote beaches and are wonderful places to work and travel.
The outback gets so hot and dry because a high pressure ridge sits over it most of the time. This high pressure ridge is the result of the relationship between the earth and the sun. Because our planet is a sphere, more of the sun's energy is focussed around the equator than at the poles.
The short answer is yes, you need to wear sunscreen year-round in Aotearoa New Zealand due to the high intensity of our UV rays. Even in Autumn and Winter.
In New Zealand, its maximum summer value is generally about 12, but it can exceed 13 in the far North. In winter it reaches peak values of 1 or 2. Values of 10 or more should be considered as "extreme". At high altitude tropical sites (eg Mauna Loa Observatory, Hawaii), the UV Index can exceed 20.
The sunniest areas, Bay of Plenty, Hawke's Bay and Nelson/Marlborough, receive over 2,350 hours of sunshine. As New Zealand observes daylight saving, during summer months daylight can last up until 9.30pm.
The lowest values occur in June-July where the UV Index averages less than 2 over Tasmania, increasing to almost 8-9 in far northern Australia.
Perth, Western Australia
In fact, it's officially the sunniest capital city in the world, with an average of eight hours of sun per day, year-round. It's wonderfully close to Fremantle and Rottnest Island too, so you can take home a suitcase full of brightly-lit quokka selfies.
Australia has some of the highest levels of UV radiation in the world – in fact, UV radiation is strong enough to cause sunburn in as little as 11 minutes on a fine summer day. UV radiation from the sun is also one of the best natural sources for vitamin D so a balance is important.