(CNN) While the ozone hole over Antarctica typically grows in September and October, scientists observed the smallest ozone hole since they first began observing it in 1982, according to a joint release by NASA and NOAA.

Unusual weather patterns in the upper atmosphere limited depletion of ozone, the layer in our atmosphere that acts like sunscreen and protects us from ultraviolet radiation.

On September 8, the ozone hole reached a peak of 6.3 million square miles and then shrank to less than 3.9 million square miles, according to the report. Usually, the hole would grow to reach 8 million square miles.

"It's great news for ozone in the Southern Hemisphere," said Paul Newman, chief scientist for earth sciences at NASA's Goddard Space Flight Center. "But it's important to recognize that what we're seeing this year is due to warmer stratospheric temperatures. It's not a sign that atmospheric ozone is suddenly on a fast track to recovery."

The annual ozone hole forms when rays from the sun interact with the ozone and man-made compounds such as chlorine and bromine to deplete the ozone, according to NASA. This occurs during late winter in the Southern Hemisphere.

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