The invention relates to a method and a device for monitoring risky atmospheric areas.The invention relates to an onboard device connected to meteorological measurement systems making it possible to calculate danger detection areas in front of the aircraft in order to detect potential areas of penetration of the aircraft into risky atmospheric areas.The areas of intersection between the detection areas and the risky meteorological areas are calculated according to the trajectory of the aircraft stored in the navigation system.The method makes it possible to generate alerts and force the display of the meteorological situation in front of the aircraft in case of danger.