French agencies said almost 200 people became sick after eating mushrooms.
A total of 181 cases of poisoning were recorded in the last two weeks of September.
From July to the end of August, poison control centers recorded 15 to 50 cases per week.
Impact of weather conditions
Five serious cases have been recorded since July, said The French Agency for Food, Environmental and Occupational Food and Safety (ANSES), la Direction générale de la santé (DGS) and French Poison Control and Monitoring Centres (CAPTVs).
Weather conditions have encouraged mushroom growth and led to an increase in the number of poisonings
The poisonings result, in the majority of cases, from confusion with edible mushrooms.
Last year, ANSES said almost 100 people were poisoned from eating mushrooms.
Three cases were severe and most resulted from confusion with other edible mushrooms.
Peak in Belgium
The Agence Fédérale pour la Sécurité de la Chaîne alimentaire (AFSCA) in Belgium said Le Centre Antipoisons receives between 300-500 calls involving mushrooms, with a peak between June and September.
The center has received more than 300 calls this year and 134 just in August.
Le Centre Antipoisons said the only way to distinguish toxic and edible fungi is to have knowledge of the distinctive characteristics of different species.
The most frequent calls are for children under the age of four who taste a piece of mushroom found outside. Given the small quantities swallowed, this type of accident is generally not serious.
Calls for sick people after a meal of wild mushrooms are fewer but can be more serious because the higher quantities consumed.
Health consequences can be severe (severe digestive disorders, liver damage that may necessitate a transplant) or death.
Symptoms usually begin to appear 12 hours after consumption.
Meanwhile, a RASFF notification has been made by Germany regarding possible presence of poisonous mushrooms - Amanita phalloides from the Netherlands.
In Krefeld, a family of five suffered poisoning after buying mushrooms on a market at Mevissenstraße at the beginning of October.