A climate change report has concluded that snowfall levels could halve over the next 80 years.
The report, by the National Institute of Water and Atmospheric Research (NIWA) says snow depths could reduce to as much as 80% of the normal base by 2040 and drop as low as 50% by 2090.
Ski field operators say that means they will likely have to rely heavily on costly snow machine technology to keep their fields open.
Mt Ruapehu and Coronet Peak operators say they use some of the best snow making technology in the world.
But their machines only work in temperatures below zero degrees, so Mount Ruapehu is looking at buying one that can operate at any temperature.