Statistically averaged variability of the aerosol component has been studied based on data of spectral measurements of AOT in Tomsk. Characteristic variations of the particle size spectrum of atmospheric hazes occurring at increase of the atmospheric turbidity are analyzed based on inversion of the spectral data. Estimates show that the increase of atmospheric turbidity is stipulated, on the whole, by growing content of accumulation fraction of aerosol. It is characteristic of the atmosphere under conditions of increased turbidity that pronounced medium size particle mode is formed. Analysis of histograms of distribution density ς(τ) of the spectral values τ(λi) over the interval of the within-year variability (repeatability) performed for years from 2000 until 2002 has shown that, despite a noticeable interannual difference in statistical distribution of AOT values, all histograms in the annual measurement series of the repeatability have a pronounced maximum and a stable interval of the most probable values.