Holiday home rental bookings have also spiked since the snow started falling and the school holidays kicked off, Bachcare said.
But meteorologists are forecasting heavy rain for many areas from tomorrow -- including Ruapehu, Auckland and the West Coast of the South Island.
MetService meteorologist Rebekah LaBar said temperatures should pick up this week as a front crosses the country.
A weather watch is in place for heavy rain along the Coromandel Peninsula and in the western Bay of Plenty tomorrow.
Northland and Auckland should get some rain, and thunderstorms were possible for Auckland and the West Coast.
"There will still be a lot of places that are going to be seeing somewhat showery weather as the northerlies are replaced by more westerly and southerly flow that will keep the temperatures somewhat mild.
"Then they will drop down towards the end of the week."
MetService has forecast occasional rain for Whakapapa and Turoa tomorrow morning, becoming persistent and heavy in the afternoon. Both fields were looking at a high of -3C.
Mt Ruapehu executive manager Simon Dickson said it was unfortunate the weather was not shaping up well for the next couple of days.
But the rain was expected to clear later on Friday so it could be looking better for the weekend.
Despite the forecast, it was more than likely beginners slopes at Turoa and Whakapapa would remain open tomorrow, Mr Dickson said.
He said it had been a "perfect last few days" on the slopes.
"It was perfect timing. We had three or four days of really heavy snow last week and then all of a sudden on Saturday the skies cleared in the morning.
"It has been really quite fantastic since."
Bachcare founder and managing director Leslie Preston said the rental accommodation agency had seen an increase of more than 50 per cent in forward bookings for the rest of the season.
"The skifields are in great shape and we are looking forward to a busy season," she said.
Marketing and communications manager for The Remarkables ski field Mel Hillstead said the number of people visiting the Queenstown field increased every day.
MetService predicted some showers for the field over the next two days, before a fine and clear Friday afternoon.
A high of 1C was forecast for tomorrow, while a high of just -4C was on the cards for Thursday.
"We are well into the thousands. We have been really lucky with the weekend, and yesterday as well we have had light blue skies and sunny days which has been fantastic."
Tomorrow's forecast:
Whangarei: Rain, chance heavy thunder, easing late. Fresh northeast. High 17C, low 12C
Auckland: Occasional rain, persistent in the afternoon, heavy at times. Strong northeasterlies. High 15C, low 10C
Hamilton: Rain at times, persistent and heavier in the afternoon. Fresh northeast. High 14C, low 8C
Tauranga: Showers turn to rain, heavy at times. Strong northeast. High 15C, low 11C
Wellington: Occasional rain develops in the morning. Northerly strengthens. High 14C, low 10C
Christchurch: Few spots morning rain, then fine. Fresh northeast eases. High 12C, low 3C
(Source: MetService)