By Olav Mellingsater - Special to CNN
A higher demand for butter as a result of low-carb diets and increased interest in natural, home-cooked meals is one reason for the shortage, according to Tine, the country's largest farmer-owned dairy cooperative.
A rainy summer reduced the quality of animal feed, decreasing milk production in Norway this year by 20 million liters (5.3 million gallons) compared with the same period last year, the cooperative said.
The Norwegian government has responded to the crisis by reducing tariffs on milk product imports, the country's agricultural authorities said.
But many stores have been rationing how much butter they sell.