(Bloomberg) -- The freezing weather engulfing Scandinavia and much of northern Europe will intensify next week, straining the region’s fragile power balance as demand peaks and a large nuclear plant shuts for repairs. 

Temperatures in Stockholm and Oslo will plunge to almost 10 degrees Celsius (18 degrees Fahrenheit) below the seasonal average, according to Maxar Technologies Inc. In western Europe, only Spain and southern Italy are escaping the cold blast, the forecaster said. 

With southern Sweden already one of Europe’s most power-stressed regions, a nine-day halt to the nation’s biggest nuclear reactor from Friday will test the grid further. 

“Supplies in Sweden are stable, but strained,” the Swedish Energy Agency said in a statement. “There’s a risk of shortages during the winter and that uncertainty will markedly increase when Oskarshamn-3 shuts.”  

Power prices for Friday in southern Sweden jumped to their highest since Sept. 1, the height of the crisis, in an auction on the Nord Pool exchange. 

Sweden’s Biggest Nuclear Reactor to Halt for Repairs in December

Elsewhere in Europe, temperatures could also fall below long-term averages, Dale Mohler, a meteorologist with commercial forecaster AccuWeather Inc. said in an interview. The UK and northern France could be as much as 5.5 degrees Celsius colder than usual, with Germany and Poland 2 to 3 degrees below seasonal norms. Northern Italy could also get chilly, he said. 

UK Set for Snowy and Cold Weather as Wind Power Output Drops

There is also a chance that parts of Germany, Poland, the Czech Republic and Slovakia could get a weekend storm, with as much as 10 to 20 centimeters (4 to 8 inches) of snow, Mohler said. The UK could also get some snow, mainly in northern Scotland, in coming days with wintry showers reaching down the east coast of England.

In Ireland sub-zero temperatures and low wind are expected to put the electricity system under pressure, according to the Irish Times. Talks have been taking place between the government and providers about potentially reducing power supplies to large energy users such as data centers, the newspaper reported.

--With assistance from Morwenna Coniam.

(Updates with power price for Friday in fifth paragraph.)

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