Snow in and of itself will not effect the SunPump. The SunPump uses a refrigerant that boils at -50°C (-58°F). It generates heat proficiently when the outdoor temperature is above -15°C (5°F). So long as the outdoor temperature does not fall below -15°C, the SunPump will continue to function proficiently, day and night, regardless of snow. A built-in 7500 watt generator kicks in if the temperature ever falls below -15°C, insuring that your home and domestic hot water always remain heated.