Last month in mainland France there were 323 road deaths, including 81 motorcyclists, which is a rise of 8.8% compared to September 2017.
Over the same time period, traffic accidents involving physical injury rose 5.6% and the number of people injured was up 4.3%.
The French road safety agency (Sécurité routière) said the lack of rain across southern France encouraged more motorcycle trips, which in turn led to more motorcycle accidents, reported the AFP news service.
On the other hand, Sécurité routière said on 18 October that 2,037 people were hospitalised for more than 24 hours following a traffic accident in France last month, down by 14.9% compared to September 2017.
The agency noted that overall the third quarter was one of the safest on record. There were fewer than 900 road deaths.
Despite the spike in September, traffic fatalities were down year-over-year by 5.5% in July and 15.5% in August.