1. A meteorological information processing device, comprising: processing circuitry configured to: detect a location and three-dimensional velocity of a rain cloud in an overlapping area of each detectable area detected by at least three radars including a first and second radar that each include a single-polarization radar and at least a third radar that includes a dual-polarization radar based on signals transmitted to the overlapping area from the first, the second and the third radars positioned at different locations respectively; and detect a characteristic of the rain cloud based on signals from the dual-polarization radar.