Temperatures are set to drop well below zero across much of Europe, with weather agencies warning of heavy snow in several countries.

France has issued orange warnings for frigid temperatures and snow across northern areas. Lille may see -5C (23F) on Friday, according to Weather Services International. Parts of northern Germany are also under orange warnings.

The cold has pushed up heating demand across Europe. In the UK, a combination of plummeting temperatures and low wind generation has put extreme pressure on the power system. That prompted a market warning from the grid operator on Wednesday, and multimillion-pound payments to gas-fired plants to plug gaps in supply.

In London, average temperatures are seen as low as 1C on Friday, 4 degrees below the 30-year norm. That would make it the coldest day of the winter so far in many parts of the country, with weather warnings for snow and ice in place.

It will be even colder in Germany next week, with average temperatures in Berlin forecast to drop as low as -4C on Monday, 5 degrees below the seasonal norm. Paris is set for 1C. Further south, cities such as Rome and Madrid also expect below-average temperatures.