Thermal and snow conditions of winters and winter floods on example of Zagożdżonka River. Thermal and snowy conditions in Zagożdżonka River catchment during hydrological years 2003-2013 and winter floods are presented in paper. The meteorological and hydrological data, such as maximum, minimum, mean diurnal air temperatures, daily snow cover depth, and water discharge, collected at Czarna station (WULS-SGGW) have been used. Meteorological conditions were analyzed using indexes proposed by Paczos. Temperate cold and extraordinarily low snowy winters has dominated in Zagożdżonka catchment in presented period of time. Winter floods as a result of snowmelt have been observed almost each year, except 2008 when winter was mild and extremely low snowy. The relation between winter severity index (WOz) and winter snowiness index (WSn) has been estimated, as well as the relation between winter snowiness index and maximum discharge (Qmax).