Сalculation results for local air circulation in the Norilsk valley are presented. Norilsk is located in the area with a complex topography with difference of level more than 1000 m. Orographical features in the city vicinity cause formation of mountain-and-valley circulation with a wide scatter of trajectories and a rapidly changing direction. To describe the air flow dynamics and pollutant redistribution, a numerical model of mesoscale atmospheric boundary layer was used. The model was adapted to the Norilsk natural-geographical conditions. The model estimates of sulphur dioxide fallout over the area are obtained for different meteorological situations.