Temperatures dropping close to zero in coming days will pose the first real test of the resilience of France's electricity grid amid warnings over possible power cuts, though President Emmanuel Macron urged the French not to panic.
French utility EDF has faced an unprecedented number of outages in its nuclear reactor fleet following repair work, reducing output to a 30-year low and adding major stress as Europe scrambles to cope with the impact of the war in Ukraine.
After an unusually mild November helped reduce electricity use, temperatures dropped on Monday and are set to hover around zero later this week and next.
While there had initially been concerns for Monday, lower than forecast nuclear availability was offset by higher imports from all of France's neighbours and high production from gas-fired power plants.
RTE's EcoWatt alert app - which the government is urging people to download to be warned of peaks in demand or risk of cuts - remained green.
"The latest weather forecasts show that from the weather side, the coming Monday Dec. 12th will be even tighter," said Refinitiv analyst Nathalie Gerl.
"Consumption is set to peak at 80 GW (versus 73 GW on Dec. 5), while wind power is expected to be below normal. Should the nuclear availability remain at 37-38 GW the supply gap risk would be much more acute than today."
Government ministers have over the past few days warned of possible power cuts on cold days in case of a gap between supply and demand, which they said would last no longer than two hours and be flagged in advance.
Macron told TF1 television at the weekend: "First of all, let us be clear: no panic! It is legitimate for the government to prepare for the extreme cases which would mean cutting off electricity for a few hours per day if we did not have enough power."
Meanwhile, further delays on nuclear reactors were announced at the weekend.
The 1.3 GW St. Alban 2 reactor restart was moved back nine days to Dec. 23 while the Chooz 2, one of the reactors that tested positive for stress corrosion, was delayed 11 days to Jan. 22.
Three other reactors were delayed at least one day and are now expected back online Tuesday.
