Scotland’s ski resorts are facing one of their most difficult seasons in years, with a lack of snow forcing them to close many of their slopes, raising questions about the impact of climate change.

Unusually mild weather – a record February temperature for Scotland of 18.3C (65F) was recorded on Aboyne in Deeside this week – has led every resort to shut down their main slopes. One has had to close entirely.

Four resorts, Nevis Range and Glencoe near Fort William, and the Lecht and Cairngorm in the Cairngorms, are using snow machines to help keep their lower slopes and nursery runs open.

A message that plays when calling the phone number for Glenshee near Braemar, one of Scotland’s oldest and best-known skiing centres, says the situation there is “pretty dire. I’m afraid we’re shut due to a total lack of snow.”

David Farquharson, the managing director at Glenshee, said his resort had just missed the snow this year. The Lecht, only a few miles away, has its lowest slopes open and has a snow-making machine.

He said there were clearly changes in the climate, but it was difficult to be certain about its impacts. “Last year we had 109 days of skiing – above average – and obviously very little this year so far. But this year isn’t over yet: we could get a big storm in March,” he said.

Chris O’Brien, the chief executive at Nevis Range, said it was investing in an industrial snow-making machine to help keep nursery slopes open, and which could produce a 100 tons of snow a day.

Their upper slopes were closed, he said, but hoped more wintry weather in the coming weeks would mean the resort could reopen over Easter. “It has been a challenging winter,” he said. “It has been unseasonably warm. However, there’s cause for optimism. We’ve been around for 30 years and the latest we have started [in previous years] was 19 February and that turned out to be a fabulous year.”

Iain Cameron, an expert in snow cover in Scotland, said: “It is important to emphasise March can be very snowy but as things stand, this is one of the most snowless winters we’ve had for 70 years.”

He maintains an annual survey of snow cover for the Royal Meteorological Society, first begun in 1954 by his mentor, Dr Adam Watson, a revered mountain ecologist who died last month.

Cameron said this year’s data was nearly identical to the figures for 1998, the year that holds the record for snowlessness.

Over the last two years, the UK’s most permanent snow patch melted away in summer. In nearly every previous year, snow was found all year round at Garbh Choire Mór in the Cairngorms but in 2017 and 2018 the patch disappeared. Although it had melted away a handful of times over the last century, it was the first time since at least the 1700s it had disappeared two years running.

Cameron was cautious about stating climate change was to blame but said it certainly suggested a long-term trend. “That has never happened before, and that’s a strong indication of where the climate is going,” he said. “That’s enough evidence to suggest things aren’t right.”

Trafford Wilson, the chief executive of the industry body Snowsport Scotland, disputed the idea that climate change could be to blame, saying seasonal fluctuations were normal.

In 2018, resorts had had the best skiing season for five years, opening from December until May with 250,000 “skier days” – equating to the number of skiing passes sold – across the five main resorts.

“The root cause of the snow not being on the mountains is we’ve had milder temperatures and we’ve had rain coming through,” Wilson said. “We’d a good level of snow cover across the mountains and the ski season was ready to go, and then the rains came through; the weather was warm and the snow has gone backwards. It has retreated.”

He said Scotland was still open for snowboarding, which requires shorter runs, and pointed to its network of dry and artificial slopes, ranging from Europe’s longest dry slope at Hillend near Edinburgh to an indoor skiing centre at Braehead near Glasgow.