Cold temperature extremes are a natural aspect of the climate that occur annually, leading to challenges in agricultural, industrial, and economic sectors, as well as contributing to road accidents. Severe temperature drops can have undesirable effects on various aspects of life and activities for both humans and plant life conditions. The purpose of this study is to examine the synoptic patterns influencing extreme cold waves in northwestern Iran. To achieve this, daily minimum temperature data from 36 synoptic stations in the northwestern region of the country were utilized for the period between 1986 and 2017 Using the standardized cold days index with a threshold value of 1.2 to identify cold wave days, monthly counts of cold wave days were extracted for each station. Applying factor analysis to the geopotential height at the level of cold wave days, four influential patterns for the formation of extreme cold waves in northwestern Iran were identified. The results of analyzing these patterns indicate that the synoptic systems governing the cold wave events ito the advection of cold air masses from northern latitudes into this area. At the 500 hPa level, the presence of a ridge, the occurrence of a blocking pattern, or the establishment of a persistent western arm of a deep trough over northwestern Iran contributes to mid-level atmospheric convergence.strengthens dynamic subsidence and stability in the lower atmospheric levels, enhancing the advection of cold upper-level air into the region. Consequently, these factors lead to the formation of extreme cold waves in northwestern Iran.