The missing man is believed to be a farmer who was swept away in his tractor by a torrent of flood water after storms hit the department of Haute-Loire in south central France.
The 27-year-old was swept away on Tuesday afternoon in the village of Brignon. According to reports he was helping firefighters find a way to a house an elderly person who was stranded due to flood waters when his vehicle was swept away.
Rescue teams continued to search for him on Wednesday morning.
Two kayakers were also reported missing in the same area but have since been accounted for.
Villages in the department were badly hit by hail stones, strong winds and floods after river levels rose rapidly following downpours.
Houses were submerged and cars were taken away by the powerful torrents. Roads were left blocked by fallen trees.
#Inondations à Costaros en Haute-Loire après les cumuls de pluie énormes dans le secteur. Vidéo de Florian Badon. @VISOV1 @departement43 pic.twitter.com/XKUlHXo8M8
— Météo-Contact (@MeteoContact) June 13, 2017
On Wednesday it was the turn of 12 departments in the south and east of the country to be placed on Orange alert for violent storms (see map below)
An orange alert warning for storms means the public are asked to be vigilant especially when travelling and taking part in leisure activities.