A cold snap hit the central North Island on the weekend, with more cold weather to come, according to MetService.
Snow was seen on Mt Tarawera, in Mamaku, and all the way up to Waiotapu on Saturday with even colder temperatures predicted for tonight and tomorrow morning.
Power was cut to people living on the Taupo plains and, according to long time Taupo resident and amateur weatherman Walter de Bont, it was the coldest day he had recorded since he began taking records in 1962.
"It was the most snow I've ever seen in Taupo and we have also had a lot of rain with 39mm in the last 24 hours.
"Saturday was also the coldest day ever recorded with a maximum not higher than 3.4C, and that is cold."
He said the previous lowest daytime maximum he had recorded was 5.2C.
Rotorua was expected to drop to -3C overnight tonight with Taupo looking at -5C.
Tomorrow night temperatures are expected to drop to -1C in Rotorua and -2C in Taupo.
The rest of the week will remain cold with lows in Rotorua expected to reach between 2C and 4C.
Taupo will be even colder with lows between 0C and 1C until Friday.
Unison Networks said it had conducted aerial patrols and were waiting on a final thorough assessment, but damage to rural high country areas appeared to be significant.
Unison relationship manager Danny Gough said as of yesterday afternoon there were about 500 customers still without power.
"The biggest areas impacted are those customers in Tutira - 178 without power, and also the Taupo plains - 189 without power.
About 40 customers were also still without power in the rural parts of Rotoma and Reporoa in Rotorua as of yesterday afternoon.
He said the company was urging customers in outlying areas to make preparations for the possibility of days without power due to extensive damage to the network.
"It will be an extensive restoration effort and we will have all crews dedicated to this once we ascertain the extent of the damage.
He said helicopters were ready on standby for both Transpower and Unison to carry out fly overs in the Taupo plains.