FrostList

When to Winterize Your RV in Idaho Falls, ID

ON TRACK94 days until first 28°F freezeOct 13

Aim to winterize your RV in Idaho Falls by October 3, roughly a week and a half before the median first 28°F freeze of October 13, which one fall in ten shows up by September 27. Plan for the early end: the one-in-ten date lands about 16 days before the median.

OUTLOOK

Typical first first 28°F freeze near Oct 13; local deadline about Oct 3. The live 10-day outlook loads here.

Local freeze dates for Idaho Falls

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Sep 17Oct 1Oct 15
28°F (hard freeze)Sep 27Oct 13Oct 27
24°F (severe)Oct 9Oct 25Nov 8

NOAA station: Idaho Falls - Kifi · 1.9 mi away · 4,742 ft elevation.

For Idaho Falls, the nearest NOAA station with freeze data is Idaho Falls - Kifi, 1.9 miles out at 4,742 feet. Median first-freeze dates there run 32°F by Oct 1, 28°F by Oct 13, 24°F by Oct 25. Year to year the 28°F date has ranged from Sep 27 to Oct 27 — about 30 days apart. Spring's last 32°F freeze clears around May 9. Snowfall averages 66 inches a year, first reaching an inch near October.

The freeze arrives in two steps in Idaho Falls: 32°F around Oct 1, then a hard 28°F near Oct 13. Year to year, the first 32°F night has fallen anywhere from Sep 17 to Oct 15 — about 28 days apart. Spring's final freeze lands near May 9 and as late as Jun 2, so that is when outdoor water and stored gear can safely come back online. With about 66 inches of snow a year, roof, snow-blower, and ice-dam prep all belong on the same calendar.

Your rv checklist

  1. Drain the fresh, gray, and black tanks, then drain the water heater only after it has cooled and lost pressure.
  2. Bypass the water heater so you do not waste six gallons of antifreeze filling the tank.
  3. Blow out the lines with a compressor at about 30–40 psi, then pump non-toxic RV antifreeze through every faucet until it runs pink.
    Helpful gear: RV antifreeze (6-pack) — Recommended pick
  4. Use a water-pump converter kit to draw antifreeze straight from the jug through the plumbing.
    Helpful gear: Water pump converter kit — Recommended pick
  5. Pour a cup of antifreeze into each drain trap and the toilet to protect the seals.
  6. Fit a blow-out plug at the city-water inlet so you can clear that line too.
    Helpful gear: Blow-out plug — Recommended pick
  7. Remove batteries or put them on a maintainer, and store them off a cold concrete floor.
  8. Cover roof vents, close the propane, and set out traps or deterrents so mice do not move in.

What to have on hand

RV antifreeze (6-pack)
Non-toxic pink fluid for the fresh-water plumbing and traps.
Recommended pick
Water pump converter kit
Siphon kit that draws antifreeze straight through the pump.
Recommended pick
Blow-out plug
Adapter that lets a compressor clear the lines before antifreeze.
Recommended pick
Heated fresh-water hose
For anyone staying hooked up through a cold snap.
Recommended pick

What this means locally

Against its neighbors, Idaho Falls (first freeze Oct 13) runs about a week ahead of Pocatello (Oct 24) and close to Logan (Oct 14). Across Idaho, local prep deadlines in our data range from Oct 3 to Oct 22, so a statewide rule of thumb would miss Idaho Falls by weeks. In Idaho Falls, that same cold is your cue to shut down your sprinklers and winterize a boat.

Other winter jobs in Idaho Falls

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

Sprinklers → Oct 3Frozen pipes → Sep 17Ice dams → Sep 15Car battery → Oct 13Snow blower → Sep 24Sump pump → May 9Boat → Oct 6Motorcycle → Oct 1

See the full Idaho Falls winter checklist, in order →

Frequently asked questions

At what temperature do RV pipes freeze?
An RV's exposed plumbing and thin-walled tanks can begin to freeze once temperatures sit in the mid-20s for a few hours, sooner than a house because there is little insulation around the lines. That is why the winterizing deadline tracks the first 28°F freeze rather than the first light frost.
How much RV antifreeze do I need?
Most travel trailers and motorhomes take about two to three gallons of non-toxic RV antifreeze, and larger rigs more. Bypassing the water heater saves roughly six gallons you would otherwise waste filling the tank. Buy an extra jug; stores sell out once the first freeze warnings hit.
Can I just use my RV furnace instead of winterizing?
Relying on the furnace is risky. A propane run-out, a tripped breaker, or a dead battery during a cold night leaves the plumbing unprotected, and the furnace may not keep the underbelly and bays warm enough anyway. Draining and adding antifreeze is the dependable way to protect the system.
How do I winterize an RV water heater?
Let the tank cool and lose pressure, then drain it and, if fitted, pull the anode rod. Do not add antifreeze to the water heater tank; instead, set the bypass valves so antifreeze skips the tank and fills only the lines. Fresh antifreeze in an unbypassed heater just wastes several gallons.
When is it safe to de-winterize an RV in Idaho Falls?
Wait until the last spring freeze has passed, which averages near May 9 here. De-winterize by flushing the antifreeze from the lines, sanitizing the fresh tank, and checking for leaks before a trip. Reopening too early risks a surprise late freeze on a charged system.
Do I need to winterize an RV stored indoors?
A reliably heated indoor space that stays above freezing protects the plumbing, so full winterizing may not be needed. But an unheated garage or barn can still drop below freezing on a cold night. If you cannot guarantee the space stays warm, winterize to be safe.

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