Astronomer and Otago Museum Director Dr Ian Griffin told Midday Report it was the best storm in about seven years.
"This time of the year is a really great time for auroras because the earth's magnetic field and the sun's magnetic field are lined up," he said.
Griffin said the geomagnetic storm was caused by the sun throwing some material at the Earth a couple of days ago, which then interacted with our magnetic fields and made our atmosphere glow.
Geomagnetic storms are normally caused by sustained periods of high-speed solar winds, and importantly a southward directed solar wind magnetic field, according to the US Space Weather Prediction Center.
The storm was also timed perfectly with a full moon, which Griffin said brightened up the sky even further.
He said it was a phenomenal morning, as the sky lit up with green and red colours in the early hours of the morning in Dunedin.
"It was just a wonderful sight," he said
"As the sky brightened, you could see the aurora in the background, and the moon setting."
He encouraged people to go out on Monday night to see Aurora Australis.
"Although the storm seems to be fading a bit, there may well be some auroras out there tonight," Griffin said.
"If you've got a clear sky, and a good view to the south, wherever you are in the country - why not go out this evening and try to see if you can see an aurora?"
