Method for warning of lightning having a system of a plurality of wind turbines, wherein the wind turbines each stand at a location (1.1, 1.2,... m.n) and each of the plurality of wind turbines has a sensor arrangement for detecting an environmental parameter, comprising at least a wind gauge, a temperature sensor and/or a moisture sensor, wherein the sensor arrangement has an additional sensor, that is to say, a field mill, for detecting electrical fields, and the method comprises the following steps: - detecting at least one value for the environmental parameter, at least comprising an electrical field, using the sensors (21, 22, 23, 24) of the sensor arrangement having the plurality of wind turbines; and - evaluating the at least one value for the environmental parameter for predicting the lightning warning for the locations (1.1, 1.2,... m.n) of the plurality of wind turbines, characterised in that - in the system the plurality of wind turbines are connected to a common central server, wherein the method further comprises the following steps: - transmitting the at least one value for the environmental parameters from the plurality of wind turbines to the server; - producing a chart with the at least one value for the environmental parameter and the location (1.1, 1.2,... m.n) of the plurality of wind turbines; and - evaluating the chart for predicting the lightning warning for the locations (1.1, 1.2,... m.n) of the plurality of wind turbines, wherein - with each sensor arrangement of the plurality of wind turbines a plurality of values for the environmental parameter are detected, and with the plurality of values for the environmental parameter a plurality of charts are produced and evaluated, and the plurality of charts are combined with each other, wherein, - based on the evaluation of the plurality of charts, probabilities for a lightning strike are associated with the locations (1.1, 1.2,... m.n) of the plurality of wind turbines, wherein for the establishment of the probabilities standard models and/or experience values from the weather forecast are used, wherein - the plurality of values for the environmental parameter are selected from the following group of values: wind strength (21.1a), wind direction (21.1b), temperature (22.1), air humidity (23.1), air pressure, electric field strength (24.1), magnetic field strength and electromagnetic field strength, and - the probabilities of a lightning strike are compared with limit probabilities and a lightning warning is output for the locations (1.1, 1.2,... m.n) of the plurality of wind turbines at which the probability of the lightning strike exceeds the limit probability, and the lightning warning is output in the form of a warning message. - detecting at least one value for the environmental parameter, at least comprising an electrical field, using the sensors (21, 22, 23, 24) of the sensor arrangement having the plurality of wind turbines; and - evaluating the at least one value for the environmental parameter for predicting the lightning warning for the locations (1.1, 1.2,... m.n) of the plurality of wind turbines, characterised in that - in the system the plurality of wind turbines are connected to a common central server, - transmitting the at least one value for the environmental parameters from the plurality of wind turbines to the server; - producing a chart with the at least one value for the environmental parameter and the location (1.1, 1.2,... m.n) of the plurality of wind turbines; and - evaluating the chart for predicting the lightning warning for the locations (1.1, 1.2,... m.n) of the plurality of wind turbines, wherein - with each sensor arrangement of the plurality of wind turbines a plurality of values for the environmental parameter are detected, and with the plurality of values for the environmental parameter a plurality of charts are produced and evaluated, and the plurality of charts are combined with each other, wherein, - based on the evaluation of the plurality of charts, probabilities for a lightning strike are associated with the locations (1.1, 1.2,... m.n) of the plurality of wind turbines, wherein for the establishment of the probabilities standard models and/or experience values from the weather forecast are used, wherein - the plurality of values for the environmental parameter are selected from the following group of values: wind strength (21.1a), wind direction (21.1b), temperature (22.1), air humidity (23.1), air pressure, electric field strength (24.1), magnetic field strength and electromagnetic field strength, and - the probabilities of a lightning strike are compared with limit probabilities and a lightning warning is output for the locations (1.1, 1.2,... m.n) of the plurality of wind turbines at which the probability of the lightning strike exceeds the limit probability, and the lightning warning is output in the form of a warning message.