Among various contributors to urban heat islands, anthropogenic heat flux (AHF) plays a particularly important role during cold waves due to increased energy demand. In this study, we examined the urban weather characteristics of the Seoul Metropolitan Area, as simulated by an urban canopy model, through an AHF sensitivity experiment for the region during a cold wave. We used the Weather Research and Forecasting-Urban Canopy Model (WRF-UCM) with prescribed AHF values for January 2017 to conduct the experiment. Sensitivity experiments were conducted with AHF scaled to 0, 1, 2, and 4 times the baseline value. The model underestimated the air temperature and relative humidity by about 1 o C and 20%, respectively, and overestimated the wind speed by 1.5ms1 without AHF. Doubling the anthropogenic heat flux led to a notable decrease in the root mean square error and mean bias error, particularly for temperature. These results suggest that, to more accurately reproduce urban weather conditions, larger amounts of anthropogenic heat flux should be prescribed during extreme cold events.