Acoustic tomography is presented as a technique for remote monitoring of meteorological quantities. This method and a special algorithm of analysis can directly produce area averaged values of meteorological parameters. As a result, consistent data will be delivered for validation of numerical atmospheric micro-scale models. Such a measuring system can complement conventional point measurements over different surfaces. The procedure of acoustic tomography uses the horizontal propagation of sound waves in the atmospheric surface layer. The state of the crossed atmosphere can be estimated from measurements of travel time of acoustic signals between sources and receivers on different points in a tomographic array. Derivation of area averaged values of the sound speed and furthermore of air temperature results from the inversion of travel time values for all possible acoustic paths. Thereby, the applied straight-ray two-dimensional tomographic model is characterised as a method with small computational requirements and simple handling, especially, for online work.