But Lauder-based Niwa atmospheric scientist Dr Richard Querel said there was no need for alarm.
"Messages saying we need to put on more sunblock because of the ozone hole — that’s not true.
"It’s not at all related to the ozone hole.
"That’s an ongoing misconception that needs to be constantly battled."
He said ozone molecules absorbed ultraviolet radiation from the sun, acting like sunscreen for life on Earth.
Too much ultraviolet radiation can cause problems such as skin damage and a fall in ocean phytoplankton which can impact the food chain.
But the hole was over the Antarctic, not New Zealand.
"It will have nothing to do with the ozone over New Zealand.
"We’ll have a surplus of ozone while the hole is happening over the Antarctic — there will be a bit of a bulge over New Zealand during that time.
"So will there be extra sunburn? No, not at all.
"The biggest thing that gets people for sunburn is the angle of the sun — the higher the angle of the sun, the more likely you are to receive more ultraviolet radiation."
Dr Querel said the problem with UV and high skin cancer levels in New Zealand was due to a combination of factors: moderate climate, so it was possible to spend more time outdoors; relatively clean air (low aerosol loading); and people having a paler skin type than was suited for these UV levels.
Niwa atmosphere and climate principal scientist Dr Olaf Morgenstern said the Antarctic ozone hole typically reached its greatest extent in September or October, and disappeared in November or December.
However, the latest data shows the ozone hole formed earlier this year and was looking likely to last much longer than usual.
This was largely due to a combination of climate change and the Tonga volcanic eruption last year, he said.
"Hunga Tonga-Hunga Ha’apai blasted an astonishing amount of water into our atmosphere.
"In fact, we are seeing around 10% more water vapour than usual.
"Water vapour is a greenhouse gas that causes cooling of the stratosphere and enhances depletion of ozone by forming clouds above Antarctica.
"Additionally, the stratosphere is very sensitive to changes in temperature, with climate change causing a long-term cooling trend.
"This may be contributing to the cold and stable conditions we are presently seeing."
Dr Querel said he and fellow scientists were measuring the chemistry in the atmosphere.
"We are working with others such as Nasa and Antarctica New Zealand to see how the makeup of the atmosphere is reacting.
"We have balloon launches planned in Antarctica to take further measurements, which we will combine with Nasa’s satellite data.
He said the ozone had been recovering since the 1987 Montreal Protocol banned human-produced ozone-depleting chemicals like chlorofluorocarbons, commonly known as CFCs.
