On Saturday, a skier escaped a human-triggered avalanche after becoming caught in its path in the Craigieburn Range near Porters ski area.
In the Mackenzie district, a snowboarder triggered an avalanche that was 250 metres long and 50 metres wide near Fox Peak ski area.
No one was injured.
Both avalanches were persistent slabs that are typically difficult to detect layers buried within the snowpack and often are unpredictable.
A comprehensive search involving specialist dogs and equipment was launched on Mount Ruapehu on Sunday after the Turoa ski patrol found signs of an avalanche outside the ski area.
No one was found.
Mountain Safety Council chief executive Mike Daisley said fortunately no one was injured despite multiple close calls.
All slopes outside ski field boundaries should be treated as backcountry terrain, he said.
"Despite the proximity to a ski field, all backcountry terrain poses inherent risks that skiers and boarders need to be aware of," Daisley said.
"To safely navigate this terrain, backcountry enthusiasts need to get the NZ Avalanche Advisory avalanche forecast and adapt their plans based on the information. They must have proper training to mitigate their risk, and carry avalanche rescue equipment and know how to use it."
The council operates the Avalanche Advisory, which gave most of the 13 backcountry alpine regions a moderate or considerable avalanche danger rating over the weekend.
