NIWA's climate summary for June recorded the lowest temperature at Tara Hills, near Omarama in the Mackenzie Country, on June 24 when it fell to -21 degree Celsius.
This temperature was the fourth-lowest temperature ever recorded in New Zealand and the coldest temperature recorded in New Zealand for more than 20 years.
During the day on June 24, Tara Hills reached a maximum temperature of -9C, its lowest maximum temperature on record.
Overnight on June 24 and 25, temperatures in the central South Island plunged to well below freezing when Tara Hills recorded -19.7C and Lake Pukaki -16.3C.
They stayed well below freezing on June 25 and 26 with Omarama recording -15C and Pukaki recording -12C.
The nationwide average temperature in June was 8.9C.