PURPOSE: To provide a snowfall preventing apparatus in which the problem due to snowfall in a fan stack of a cooling water tower installed in a cold temperature area can be eliminated.

CONSTITUTION: The snowfall preventing apparatus in a cooling water tower fan stack comprises a warm water sprinkling tube 2 disposed along the inner periphery of a fan stack 6 above a ventilating fan 7 and having a plurality of spray nozzles 11 for injecting warm water flowing therein, a water collecting sheet 3 for recovering the warm water separated from the tube 2 or the water generated by melted snow, a water tank 4 having a heater 15 for heating the water recovered by the sheet 3, and a pump 5 for supplying the heated warm water to the tube 2.