Saint-Denis sits in the Paris metropolitan region along the Seine river basin, where a temperate oceanic climate keeps rainfall fairly moderate and evenly spread across the year.
Just north of central Paris, the city sits low in the Seine basin, an area monitored closely during the river’s periodic slow rises. The Seine’s slow, gradual response to rainfall means river flooding here typically develops over days rather than hours, as seen in the major floods of 2016 and 2018, though intense summer storms can still cause rapid local street flooding. Learn more: Flash Flood Warning Signs on Radar · Open the full Rain Map