A computer implemented method and system of instructing one or more weather drones. The method includes analysing a first data set comprising flight path data indicative of the flight paths of one or more aircrafts over a predefined time period. The method includes identifying, based on said analysis, at least one geographical region which is not intercepted by or adjacent to, any of the flight paths of the one or more aircrafts. The method includes instructing one or more weather drones to fly to the at least one geographical region.