You should start dripping your faucets when the outside temperature is around 20°F −7°C-7°C−7°C or lower, especially if it will stay that cold for several hours and your pipes are in exposed or poorly insulated areas. A slow trickle (a few drops per second) is usually enough to help prevent pipes from freezing while limiting water waste.

Key temperature guidelines

  • Begin dripping when the forecast shows temperatures at or below about 20°F −7°C-7°C−7°C for several hours or overnight, particularly if you’ve had freezing-pipe issues before or have uninsulated pipes in exterior walls, crawl spaces, basements, or attics.
  • You can usually stop dripping once temperatures are consistently above freezing (over 32°F / 0°C) and no longer expected to dip back into the low 20s.

How much to drip and which faucets

  • Aim for a slight continuous trickle, often described as 5–10 drops per minute or roughly one drop every few seconds; it just needs to keep water moving so it is less likely to freeze.
  • Prioritize faucets connected to pipes in exterior walls or unheated spaces and those farthest from your water meter, and, if possible, let both hot and cold sides run slightly to keep both supply lines moving.

Extra steps to protect pipes

  • Keep your home’s heat at about 55°F or higher, even at night or when you are away, so interior pipes stay warmer.
  • Open cabinet doors under sinks on exterior walls to let warm air reach the pipes, and add foam insulation or heat tape to exposed sections where you can.

Why 20°F is the common rule

  • Indoor pipes usually stay above freezing until outside temperatures drop into the low 20s for a sustained period, which is why many plumbers and home guides use 20°F as the point to start dripping.
  • In very drafty homes, older houses, or areas with strong wind and unheated crawl spaces, some people choose to start a bit earlier (mid‑20s) as a cautious extra margin of safety. Information gathered from public forums or data available on the internet and portrayed here.