The method for providing a warning of radiation-dose-relevant space-weather events at cruising altitudes comprises the steps of detecting radiation data of the atmospheric radiation, particularly ionizing radiation in the atmosphere, and providing a radiation model for 3D-spatially resolved estimation of a radiation field at cruising altitudes of the earth's atmosphere by use of a radiation dose rate scale based on a continuous range of values. Moreover, the 3D-spatially resolved rates of the effective radiation dose on the basis of the detected radiation data and the radiation model will be estimated. The radiation dose rate scale is divided, based on a continuous range of values, into a discrete, i.e. graduated radiation dose rate scale comprising individual successive ranges of values of increasing radiation dose rates, and respectively one index will be assigned to each range of values, wherein a first range of values is between a radiation dose rate of zero and a presettable first upper limit, a second range of values is between the first upper limit and a second upper limit which is equal to a presettable multiple of the first upper limit, and each further range of values is between the upper limit of the next smaller range of values and an upper limit which is equal to the presettable multiple of the upper limit of the next smaller range of values. As a warning, there is indicated the index of that range of values within which is situated the estimated radiation dose rate for a presettable range in the earth's atmosphere.