Complex sentence: Snow falls in New Zealand's South Island and at higher altitudes in the North Island, it is extremely rare at sea level in the North Island, with one snowfall in both Auckland and Wellington in 2011 after a period of 80 years where none occurred.
Split into simpler sentences: Snow falls in New Zealand's South Island and at higher altitudes in the North Island. It is extremely rare at sea level in the North Island, with one snowfall in both Auckland and Wellington in 2011 after a period of 80 years where none occurred.