At what temperature will a pool freeze?

It depends on if a pool is above or below ground. While air temperature affects a body of water exposed to it, so does the ground temperature. A warm ground will keep your pool from freezing at 32 degrees F. However, an above-ground swimming pool may freeze above 32 degrees F is there is a cold wind. Thus, wind chill will lower the temperature of the pool tank (especially if it is metal) and your pool will freeze faster. Try a propane or wood-fired pool heater. In cloudy Northeastern states, solar heating is ineffective. In fact, today's solar pool heaters are too weak to keep a pool from freezing at sustained below-freezing temperatures. It's always best to drain any pool in a cold winter climate. Good luck and happy swimming!