You should wrap your pipes before the first hard freeze is expected in your area, not once freezing temperatures have already arrived. As a simple rule of thumb, start protecting exposed pipes when forecasts show temperatures at or below 32°F (0°C), especially if that cold will last several hours overnight.

Key temperature guidelines

  • Wrap outdoor and unheated indoor pipes (attic, crawl space, garage, exterior walls) before your local forecast hits freezing or a “hard freeze warning.”
  • In places with frequent winter freezes, many utilities recommend insulating pipes well ahead of winter so you are not rushing when the first cold snap hits.
  • If a sudden cold front is coming and you are short on time, prioritize any fully exposed outdoor pipes and hose bibs first.

Seasonal timing

  • In colder climates, wrapping is often done in late fall so everything is protected for the whole season.
  • In milder places (like parts of Texas or the Southwest), experts suggest wrapping pipes before the first forecasted freeze of the year, because cold snaps can be brief but severe.
  • Check each fall that last year’s insulation is still intact and dry, and replace it if it’s damaged or loose.

Which pipes to wrap

  • Outdoor faucets, hose bibs, and any above‑ground irrigation or sprinkler lines should be insulated or covered.
  • Exposed pipes in unheated spaces (garages, crawl spaces, attics, basements, under sinks on exterior walls) are high‑risk and should be wrapped.
  • If your area regularly drops well below freezing, consider adding heat tape or heat cable under the insulation on the most exposed runs.

Extra steps on freezing nights

  • Let a slow drip run from a faucet on an outside wall during hard freezes to keep water moving in the line.
  • Open cabinet doors under sinks on exterior walls so warm indoor air can reach the pipes.
  • Disconnect garden hoses and shut off/drain lines to outside faucets and irrigation before or at the start of the freezing season.

TL;DR: If you are wondering “when should I wrap my pipes,” the safe answer is: as soon as the forecast shows 32°F (0°C) or lower, and ideally earlier in the season so you are always ahead of a freeze.