We report a highly stable Zn metal anode by simply controlling the operating temperature at 0 °C. Without any further protection, the Zn anode exhibits an ultra-long cycle life over 2500 h (>100 days) in Zn symmetric cells with 3 M Zn(CF₃SO₃)₂ aqueous electrolyte. This impressive performance is ascribed to the improved Zn metal corrosion resistance and compact and smooth Zn surface morphology during Zn plating/stripping at low temperatures.