How to Prevent Frozen Pipes in a Baltimore Winter

Baltimore averages 93 nights a year at or below freezing, and Baltimore City DPW warns that pipes and meters freeze when temperatures stay below 25°F. Prevent frozen pipes by holding the thermostat at 55°F or higher day and night, dripping the lowest faucet, opening sink cabinets, shutting off outdoor spigots and insulating pipes in unheated spaces. Each step below names its source.

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Pipes already frozen? Thaw them first, then come back to this list.

Before the next hard freeze

Set the thermostat to 55°F or higher.
Drip the lowest faucet below freezing.
Open cabinet doors under sinks.
Shut off and drain outdoor spigots.
Insulate pipes in unheated spaces.
Seal drafts where pipes run.

Step 1 of 7

Hold the thermostat at 55°F or higher, day and night

Keep the thermostat at the same setting day and night, and never below 55°F when you are away. Iowa State University Extension and the Institute for Business & Home Safety (IBHS) both set 55°F as the floor; the Insurance Information Institute recommends 65°F.

Insurance matters here too: NAIC notes that most homeowners policies expect a minimum indoor temperature, or the water shut off, in a vacant home.

Step 2 of 7

Drip the lowest faucet when it drops below freezing

Baltimore City DPW recommends a thin, steady stream of cold water, about the thickness of a pencil lead, from a faucet on the lowest level of your home once temperatures drop below freezing.

IBHS explains why it works: an open faucet relieves the pressure that bursts pipes, and even the slowest drip provides that relief. Drip both hot and cold lines where a faucet has both, and if the drip stops, leave the faucet open, because the pipe feeding it may have frozen.

Step 3 of 7

Open cabinet doors under sinks on outside walls

Open the kitchen and bathroom cabinet doors so warm room air circulates around the pipes, as both Baltimore City DPW and IBHS advise. Prioritize sinks on exterior walls.

Step 4 of 7

Shut off and drain outdoor spigots and hoses

Disconnect and drain garden hoses, as Baltimore City DPW directs.
Close the indoor valve that feeds each outdoor faucet and drain the line; IBHS notes homes built before 2010 typically lack frost-proof outdoor faucets.
Cover hose bibs with insulated covers, per Texas A&M AgriLife Extension.
Have a plumber add an indoor shut-off where an outdoor faucet has none, which IBHS recommends.

Step 5 of 7

Insulate pipes in attics, crawl spaces and outside walls

IBHS lists attics, crawl spaces and pipes along outside walls as the places to insulate. Foam or fiberglass pipe sleeves work for exposed runs; for heat tape or heat cable, IBHS advises choosing a product that conforms to UL 2049 and has a built-in thermostat.

Step 6 of 7

Seal drafts where pipes pass through walls

IBHS warns that pipes hit by drafts freeze even above the usual temperature thresholds. It says to seal openings where plumbing, vents and wiring pass through exterior walls, and Baltimore City DPW warns that even a little cold air from a broken window or a crack in the wall causes trouble. Iowa State University Extension adds: keep the garage door closed when water lines run through the garage.

Step 7 of 7

Drain the plumbing before a long winter trip

For a long absence, IBHS calls draining the system the surest protection: shut off the main valve, then turn on every fixture, hot and cold, until the water stops running. Where to find the main shut-off valve explains how to close it.

When Baltimore pipes are most at risk

January brings Baltimore the most freezing nights, 24 on average at BWI Marshall. December through February averages 65.6 such nights, according to NOAA’s 1991–2020 climate normals.

Average nights at or below 32°F at BWI Marshall, by month (NOAA normals, 1991–2020)
Month	Nights at or below 32°F
October	1.0
November	10.4
December	20.6
January	24.0
February	21.0
March	13.9
April	2.4

Two thresholds matter. Baltimore City DPW warns about sustained temperatures below 25°F, and University of Illinois Building Research Council tests published by IBHS found uninsulated attic pipes started freezing at 20°F outside, which BWI reaches on 20.8 nights a year. Pipes exposed to drafts freeze at warmer temperatures than either figure.

Where pipes freeze first

Iowa State University Extension names unheated interior spaces, meaning basements, attics and garages, as the most common spots. IBHS adds pipes along outside walls and anywhere a draft reaches plumbing.

Once a pipe does freeze, follow the safe thawing steps to open it back up without bursting it.

Frozen pipe prevention questions

What temperature should I keep my house to prevent frozen pipes?

At least 55°F, day and night, according to IBHS and Iowa State University Extension; the Insurance Information Institute recommends 65°F. Keep the setting constant rather than dropping it overnight.

How much should I let a faucet drip?

About the thickness of a pencil lead. Baltimore City DPW recommends a thin, steady stream of cold water from a faucet on the lowest level of the home once temperatures drop below freezing.

At what outdoor temperature do pipes freeze in Baltimore?

Baltimore City DPW warns that pipes and meters freeze when temperatures stay below 25°F for extended periods. IBHS-published research found uninsulated attic pipes start freezing at 20°F, and drafty pipes freeze at warmer temperatures.

If a pipe freezes and splits anyway

A pipe that split in the cold needs the damaged length replaced and a pressure test. Speedy Plumbing Baltimore handles that repair around the clock; details are on our 24/7 emergency pipe repair service for Baltimore page.

Sources

Checked 2026-09-13. Plumbing and safety guidance changes; follow your utility’s and insurer’s current instructions.

Frozen or split pipe?

Call Speedy Plumbing Baltimore to thaw the line and repair the damage. The line is answered 24 hours a day.

Call (410) 555-0199