Pipes start freezing once water inside reaches 32°F, but most homes see issues when outdoor temperatures stay near 20°F for several hours. Unheated areas – like crawlspaces, garages, and exterior walls – can freeze sooner, while well-insulated pipes last longer. Factors such as pipe material, insulation, wind exposure, and water movement all affect freeze timing. If you’re watching the forecast and wondering when pipes freeze, use 20°F as the point to start taking precautions.
