FrostList

When to Winterize Your RV in Kennewick, WA

ON TRACK123 days until first 28°F freezeNov 11

In a typical year, winterize your RV in Kennewick by November 1. The median first 28°F hard freeze at Kennewick's NOAA station is November 11 (1991–2020 normals); one year in ten it arrives as early as October 27. Year to year the date swings about 35 days, which is why the live outlook beats the calendar.

OUTLOOK

Typical first first 28°F freeze near Nov 11; local deadline about Nov 1. The live 10-day outlook loads here.

Local freeze dates for Kennewick

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Oct 18Oct 30Nov 15
28°F (hard freeze)Oct 27Nov 11Dec 1
24°F (severe)Nov 5Nov 25Dec 20

NOAA station: Kennewick · 1.7 mi away · 390 ft elevation.

Numbers for Kennewick come from Kennewick, 1.7 miles away at 390 feet, where the medians fall 32°F by Oct 30, 28°F by Nov 11, 24°F by Nov 25. The 28°F freeze has come as early as Oct 27 and as late as Dec 1, a 35-day spread. Spring's last 32°F freeze clears around Mar 28. Snowfall averages 2 inches a year, first reaching an inch near December.

The freeze arrives in two steps in Kennewick: 32°F around Oct 30, then a hard 28°F near Nov 11. Year to year, the first 32°F night has fallen anywhere from Oct 18 to Nov 15 — about 28 days apart. Spring's final freeze lands near Mar 28 and as late as Apr 10, so that is when outdoor water and stored gear can safely come back online. Measurable snow is rare, so the freeze near Mar 28 — not snow load — drives the local prep list.

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, Kennewick (first freeze Nov 11) runs close to Pasco (Nov 11) and later than Richland (Nov 4). Across Washington, local prep deadlines in our data range from Oct 6 to Dec 1, so a statewide rule of thumb would miss Kennewick by weeks. In Kennewick, that same cold is your cue to shut down your sprinklers and winterize a boat.

Other winter jobs in Kennewick

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

Sprinklers → Nov 1Frozen pipes → Oct 18Car battery → Nov 11Sump pump → Mar 28Boat → Nov 4Motorcycle → Oct 30

See the full Kennewick 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 Kennewick?
Wait until the last spring freeze has passed, which averages near Mar 28 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 Kennewick, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.