Freezing temperatures are one of the climatic phenomena that have the ability to cause damage in different parts. Therefore, it is very important to know this phenomenon and understand its mechanism. In this regard, in order to investigate the different tropospheric and stratospheric dimensions of Iran's pervasive ice, the minimum temperature statistics of 130 synoptic stations were used in the cold period of the year (November to March), during the statistical period of 35 years (1986-2020). Also, to study atmospheric conditions, data from the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) with a horizontal resolution of 2.5 x 2.5 degrees and data from the European Center for Medium-Range Weather Forecasting (ECMWF) ERA5 Land section with a resolution of 0.125 ×0.125 geographic degrees were used. Finally, in order to know the origin of the air mass that entered the region during the occurrence of widespread frosts, it was tracked from the Lagrangian model (HYSPLIT) in the retrograde method from three days before the cold period. The results showed that 4 dominant patterns play a role in the occurrence of widespread frosts in the region as follows. The first pattern: the Mediterranean and Black sea ridge, the second pattern: the eastern European ridge-Ganges valley, the third pattern: Eastern European blocking, the fourth pattern: polar low pressure, which is the main route of cold air and its transfer into Iran at 500 degrees It is up to 200 hectopascals.