The conclusion has been made by health authorities Santé Publique France whose latest bulletin on flu (grippe in French) outbreaks in France has classed the greater Paris region of Île-de-France as red, meaning it has reached the level of "epidemic".
Elsewhere in France eight regions are at "pre-epidemic level". Only the east of the country, plus the Rhône-Alpes-Auvergne region and Corsica are currently spared a major outbreak of the flu virus.
Last week almost 1,500 people went to emergency wards at hospitals due to the flu and 112 people were hospitalized.
"According to data the number of doctors consultations for flu has reached 98 per 100,000 inhabitants," said Santé Publique France, a steep rise on the number of cases last week.
The rise in cases will worry health authorities who last winter were forced to delay hospital operations after a deadly flu epidemic spread across the country and put a huge strain on resources.
In January this year a particularly virulent strain of the virus type A (H3N2) saw nearly 800,000 people in France consult a GP about flu-like symptoms in a matter of weeks.
In all the flu virus contributed to 14,000 deaths in France last winter, with the elderly particularly affected, especially those who lived together in retirement homes.
"For the moment, there is not a single influenza virus that dominates, it is rather a mix of different strains. There are A viruses (H1N1 and H3N2), and cases of the B virus. For the moment it is less aggressive than last year, but we won't know for sure until a few weeks time, " Dr. Sibylle Bernard-Stoecklin, from Santé Publique France told Le Parisien.
This year Health Minister Agnes Buzyn has already gathered together health chiefs to prepare for another epidemic this year. The minister is hoping emergency services including Samu and Smur are better prepared to deal with the number of patients who may require urgent care.
Patrick Pelloux who is president of the Association of Emergency Doctors said: "There is a lot of work to do. We have to deal with a permanent state of crisis."
So what's the best way to avoid getting the flu?
The flu vaccination remains the most effective way to avoid being struck down, especially for the elderly and frail. However it takes around two weeks for the vaccination to become effective.
But the flu epidemic will likely last until February so it may still be worth it. Other than that the public are advised to take steps to avoid the virus: essentially wash hands and avoid contact with people who are ill.