Automotive radars offer robust perception in adverse weather; however, their performance can degrade due to signal attenuation from contaminants on the sensor surface. This paper investigates the influence of surface snow accumulation on automotive radar detection performance through controlled experiments using both natural and machine-made snow. An automotive radar was tested for detection distance and radar cross section under varying snow layer thicknesses and densities at controlled temperatures. Experimental results show stable detection distance regardless of snow type or thickness, while radar cross section decreases with increasing snow density and compaction. Minor differences between natural and machine-made snow suggest that machine-made snow is suitable for repeatable radar attenuation studies. © 2025 IEEE.