You generally need to drip faucets when outdoor temperatures are expected to be well below freezing for several hours, especially if your pipes are on exterior walls or in unheated spaces, and you should keep them dripping until temperatures stay safely above freezing again.

Key temperature guidelines

  • Many plumbers and home-repair guides recommend starting to drip faucets when forecasts show:
    • At or below 32°F (0°C) for several hours, especially with wind and poorly insulated pipes.
* At or below about 20°F (−6°C) for 2–3 hours or more, even with better insulation, because risk of freezing rises sharply.
  • Keep faucets dripping until:
    • Temperatures are consistently above freezing during day and night, or at least above about 20°F for a sustained period.

When dripping is most important

  • Homes at higher risk:
    • Older houses with little pipe insulation or crawlspaces.
    • Pipes running along exterior walls, in garages, attics, basements, or crawlspaces.
  • Situations where you should almost always drip:
    • A hard freeze is forecast (single digits/teens Fahrenheit).
    • The power goes out during freezing weather, so your heating can’t protect pipes.

How to drip faucets correctly

  • Which faucets:
    • At least one faucet on each level or wing of your home, prioritizing those on exterior walls or farthest from the water meter.
* Include both hot and cold lines (set single‑handle faucets to the middle so both lines move).
  • How much to drip:
    • A slow, steady drip or slight trickle, often described as one drop every few seconds, is usually enough to keep water moving.

When to stop dripping

  • You can usually stop:
    • Once forecasts show temperatures staying above 32°F (0°C) and no more hard overnight freezes are expected.
* After confirming that none of your faucets or visible pipes are frozen or leaking when the cold snap ends.

Extra quick tips

  • Open cabinet doors under sinks on exterior walls so warm room air can reach the pipes.
  • Disconnect and drain outdoor hoses, and insulate outdoor spigots; these are often the first to freeze.
  • A small increase in your water bill from dripping is usually far cheaper than repairing a burst pipe and water damage.

Information gathered from public forums or data available on the internet and portrayed here.