Abstract The paper presents the mapped spatial distribution of the maximum hail days in the period 1966–2016 and the number of hailfall with different diameters and hail frequency from 2015 to 2018. The territories most affected by hail are identified, the key factor is orography. Hail with an annual frequency of occurrence is observed mainly in regions with an altitudes of more than 300 masl which influenced by the southern mountains of Siberia. The characteristics of convective clouds (height and cloud top temperature, thickness of the cloud, temperature at the condensation level) are presented according to upper-air sounding and satellite measurements. An assessment of synoptic processes on days with hail has shown an increase share of intra-mass processes, in particular, mesoscale convective systems (MCS) in the summer.