The ski industry in Japan, already hurt by the country's demographics that have aged out many from the sport, has been hit with a dose of just what it didn't need - balmy winter weather, courtesy of El Nino.

While some ski and snowboarding resorts are doing fine bolstered by visits from foreign tourists, others are having one of their worst seasons in years.

At Gunma in eastern Japan, patches of grass dot the landscape rather than snow piles. Lifts at the 80-year-old Oana resort in Minakami, a hot-springs town in the region, have run only two days this season and the number of visitors plunged about 80 percent from a year ago during the new year's holidays.

"I do nothing but pray for snow," said Motoko Hokari, who has worked at the ski resort for about 25 years. "Minakami feels stale with no visitors along the shopping streets near the station."

Overall, the number of skiers and snowboarders has declined more than half from its peak in 1998, to fewer than 8 million, according to Japan's Tourism Agency.

After leveling off from a ski boom in the 1970s and 1980s, Japan's resorts in the 2000s began benefiting from a sharp increase in foreign visitors, including Australian skiers who started coming to Japan rather than North American resorts after the U.S. terror attacks in 2001.

Still, the influx of foreign visitors hasn't been enough to make up for slackening demand from domestic skiers, as a result of an aging population that doesn't ski as much and travels less, too. And decades of deflation and a sluggish economy haven't helped the resorts or the ski-wear industry.

This winter the additional culprit is a lack of snow. The average temperature in eastern Japan in December was 1.9 degree higher than the average temperature in the period from 1981 to 2010, posting a record for the month.

Behind the unseasonable weather is what some U.S. forecasters have called the "Godzilla El Nino." In August, the National Oceanic and Atmospheric Administration predicted that the 2015 El Nino could be among the strongest since at least 1950. An El Nino pattern, a prolonged warming in Pacific Ocean sea-surface temperatures, generally causes cooler weather during summers and warmer temperatures during winters in Japan.

One economist says there is a correlation between El Nino-driven weather and consumer spending.

"There's a tendency that Japan's economy worsens when the nation has mild winter," said Toshihiro Nagahama, chief economist at at Dai-ichi Life Research Institute in Tokyo. "The warm winter is definitely not good for prospects for consumer spending and Japan's economy on the whole."

Japan, for instance, was in a recessionary phase from June 1997 to January 1999 when the El Nino pattern occurred in 1997-1998, he said.

If the average temperature in Tokyo and Osaka rises by 1 degree Celsius in October-December from the previous year, it pushes down household spending by about 0.6 percentage points and gross domestic product by about 0.3 percentage points, according to a calculation by Nagahama.

Gunma's tourism industry is certainly feeling the effects this winter. The number of visitors to ski resorts in the area from Dec. 29 to Jan. 3 fell to a record low of 166,233, according to a report released by Gunma's prefectural government.

Not all areas are suffering. Hakuba, the main venue for the 1998 Winter Olympics in Nagano, has benefited from higher altitudes with more powder snow that may be attracting skiers and snowboarders from the snow-deficient areas, according to the tourism commission of Hakuba village.

The sale of ski and snowboarding apparel and equipment is way down this season, though sales are recovering this month, said Youko Ooshima, a spokeswoman at Victoria Inc.

At Fast Retailing Co., slow sales of winter clothes for the retailer's Uniqlo casual wear brand caused it to cut its full-year operating profit forecast.