Vigilance was launched on October 1, 2001. It was created following the destructive Lothar and Martin storms of December 1999. Météo-France takes into account nine phenomena illustrated by pictograms: violent wind, heat wave (like that of 2003), rain/flooding, snow/ice, floods, thunderstorms, submersion waves, extreme cold and avalanches.
It allows the population to be warned of future meteorological risks, but also allows public authorities to prepare and mobilize teams if necessary. It shows the weather changes for each department for the next 24 hours. The map is updated twice a day, once at 6 a.m. and a second at 4 p.m.
The green vigilance does not indicate any risk or event, it is used to show the default climate of a region, without vigilance necessary.
Yellow vigilance indicates that recurring events in the regions indicated (floods, heat waves, etc.) may be “occasionally and locally dangerous”. Météo-France therefore recommends being attentive to the evolution of the situation if you practice an activity exposed to this meteorological risk.
Orange vigilance indicates dangerous phenomena. You have to be very careful about your movements and activities, follow the meteorological evolution as well as the safety instructions given by the public authorities.
Red vigilance is the maximum level in mainland France. It announces “dangerous weather phenomena of exceptional intensity”, according to Météo-France. It is therefore recommended to inquire very often about the evolution of the situation, while following the safety instructions issued, under penalty of putting your life in danger.
