A thermal transient anemometer provides mass flow rate or volume flow rate over smaller discrete regions of a larger flow field, i.e., the distribution of such rates over a predefined, larger area. The thermal transient anemometer comprises two components: a frame with a plurality of sensing cells each having a resistance wire grid and a control unit which includes an energy source which heats the resistance wire grid of each cell, measurement circuitry for determining the decay of resistance of the grid wires as they cool and computational circuitry which determines the mass or volume flow rate through each cell based upon such decay function.