In the southern town of Orthez, temperatures peaked at 28.3C -- its hottest reading for February on record.

"In the southwest, the mild weather has turned into outright spring heat, with temperatures worthy of May," Meteo France noted.

"Temperatures, already high for this season, are climbing further between Tuesday and Wednesday," the weather service noted, adding readings had exceeded 25C at multiple stations.

In the southwestern city of Biarritz, 27C was measured -- 14 degrees above normal -- along with 26C in Pau.

The warm weather comes after a long streak of rainy days in France and one of its wettest Februaries on record.

Scientists say the rising temperatures are driven by the rising greenhouse gas emissions that are causing global warming.