The present paper investigates heavy rainfall occurring in south and south east of Iran in January, 2020. During this period, Qeshm stations with 215.3, Mehristan (Sistan and Baluchistan) with 163.5 and Bandar Abbas with 161.2 mm had the highest rainfall. Within three days, of the 38 stations surveyed, 11 stations recorded more than 100 mm precipitation. The skew-T diagrams show the instability of the area's atmosphere from ground level to high levels. The amount of volatility indicators also confirms this. Synoptic maps also showed that an Omega blocking system was deployed in Western Europe. Cold weather high latitudes from the eastern edge of this blocking, which is also stretched deep into low latitudes. In the lower levels, the Sudanese system has moved northwards, becoming a dynamic system, creating a convergence center on the Red Sea that extends from the Arabian Peninsula to the Persian Gulf. Humidity has been higher in the days than in the Red Sea, Oman, and the Persian Gulf. The negative PNA index has caused the polar jet to expand to low latitudes. Other cross-linking indices have also played an important role in producing heavy rainfall.