FrostList

When to Prevent Frozen Pipes in Nampa, ID

ON TRACK94 days until first freezing night (32°F)Oct 13

In Nampa, plan for freezing nights from about October 13 onward — one year in ten by September 29 — and treat any low in the low 20s as a pipe-risk night. Cold deepens quickly here — only about 12 days separate the first frost from that hard freeze.

OUTLOOK

Typical first first freezing night (32°F) near Oct 13; local deadline about Sep 29. The live 10-day outlook loads here.

Local freeze dates for Nampa

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Sep 29Oct 13Oct 28
28°F (hard freeze)Oct 9Oct 25Nov 10
24°F (severe)Oct 22Nov 6Nov 24

NOAA station: Nampa Sugar Factory · 4.4 mi away · 2,470 ft elevation.

Numbers for Nampa come from Nampa Sugar Factory, 4.4 miles away at 2,470 feet, where the medians fall 32°F by Oct 13, 28°F by Oct 25, 24°F by Nov 6. Year to year the 28°F date has ranged from Oct 9 to Nov 10 — about 32 days apart. Spring's last 32°F freeze clears around Apr 29. Snowfall averages 10 inches a year, first reaching an inch near December.

In Nampa, freezing nights (32°F) typically begin around Oct 13 and the first hard freeze (28°F) follows near Oct 25. That first freezing night has ranged from Sep 29 to Oct 28, roughly a 29-day spread. On the spring side, the last 32°F freeze clears around Apr 29 and as late as May 18 — the green light for reopening water and de-winterizing. Only about 10 inches of snow falls in a typical year, so cold protection outranks snow removal.

Your frozen pipes checklist

  1. Disconnect, drain, and store garden hoses, then shut off and drain any interior valves that feed outdoor faucets.
  2. Insulate exposed pipes in the garage, crawl space, and along exterior walls with foam sleeves rated for the pipe size.
    Helpful gear: Foam pipe insulation sleeves — Recommended pick
  3. On nights in the low 20s, let a pencil-thin stream of water drip from the faucet farthest from where the line enters.
  4. Open cabinet doors under kitchen and bathroom sinks on outside walls so household heat reaches the plumbing.
  5. Add self-regulating heat cable to the runs most likely to freeze, such as a pipe in an unheated garage.
    Helpful gear: Self-regulating heat cable — Recommended pick
  6. Cap outdoor faucets with insulated covers once the hoses are off.
    Helpful gear: Outdoor faucet covers — Recommended pick
  7. Know where your main shutoff is and confirm it turns; a fast shutoff limits water damage if a line lets go.
  8. If you travel, keep the thermostat at 55°F or higher and ask someone to check the house during a cold snap.
    Helpful gear: Wi-Fi water leak sensor — Recommended pick

What to have on hand

Foam pipe insulation sleeves
Split foam tubing for exposed pipes in crawl spaces and garages.
Recommended pick
Self-regulating heat cable
Thermostatic cable that warms vulnerable runs only when it is cold.
Recommended pick
Outdoor faucet covers
Insulated caps for hose bibs once the hoses come off.
Recommended pick
Wi-Fi water leak sensor
Puck that pings your phone the moment it senses water.
Recommended pick

What this means locally

Compared with nearby cities, Nampa's first-freeze date near Oct 13 sits about a week ahead of Meridian (Oct 21) and about a week ahead of Caldwell (Oct 18). Idaho's deadlines span Sep 17 to Oct 5 statewide — one date for all of Idaho would be off by weeks for Nampa. Once you know Nampa's freeze date, use it to shut down your sprinklers and check your car battery too.

Other winter jobs in Nampa

Every task below is dated to Nampa's own freeze and snow normals.

Sprinklers → Oct 15Ice dams → Nov 15Car battery → Oct 25Snow blower → Nov 24Sump pump → Apr 29RV → Oct 15Boat → Oct 18Motorcycle → Oct 13

See the full Nampa winter checklist, in order →

Frequently asked questions

At what temperature do pipes freeze?
Pipes generally come under risk when the temperature outside falls to about 20°F, the threshold many guides use for taking action. Pipes in unheated or exterior-wall spaces freeze sooner than well-insulated interior runs. Wind and poor insulation lower the effective temperature, so a windy night in the mid-20s can be as risky as a still night in the low 20s.
Should I drip my faucets tonight in Nampa?
If the overnight low is forecast at or below about 20°F, letting a thin stream run from the faucet farthest along the line is a low-cost precaution. Moving water is slower to freeze and relieves pressure. Check tonight's low against the live outlook above; freezing nights here typically begin around Oct 13.
How long does it take for pipes to freeze?
There is no fixed clock; it depends on pipe location, insulation, and how far below freezing the air drops. An exposed pipe in a windy, unheated space can freeze in a matter of hours during a hard cold snap, while a protected interior pipe may never reach freezing. The colder and windier it is, the faster it happens.
Which pipes freeze first?
The most exposed pipes freeze first: outdoor hose bibs, and lines in unheated garages, crawl spaces, attics, and along exterior walls. Pipes under sinks on outside walls are common trouble spots. That is why disconnecting hoses and opening cabinet doors on cold nights are two of the highest-value steps.
Does homeowners insurance cover burst pipes?
Sudden, accidental water damage from a frozen pipe is often covered, but insurers may deny a claim if the home was left unheated or the damage is judged to be from neglect. Coverage varies by policy. Keeping the heat on and taking reasonable precautions helps protect both your home and your claim.
What temperature should I keep my house if I'm away?
A common recommendation is to keep the thermostat no lower than 55°F while you are away so interior walls stay warm enough to protect the plumbing. Leaving cabinet doors open and having someone check the house during a cold snap adds a margin of safety, especially for pipes on exterior walls.

Data: NOAA 1991–2020 normals via Nampa Sugar Factory, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.