Siberian algid arctic below zero biting bitter bitterly cold bleak boreal brisk brumal cold cold as charity cold as death cold as ice cold as marble crisp cutting dead as mutton freezing freezing cold frigid gelid glacial hibernal hiemal hyperborean ice-cold ice-encrusted icelike icy inclement keen nipping nippy numbing penetrating piercing pinching raw rigorous severe sharp sleety slushy snappy stiff stone-dead subzero supercooled winterbound winterlike wintery wintry