FrostList

When to Winterize Your RV in Corvallis, OR

ON TRACK129 days until first 28°F freezeNov 17

Corvallis's median first 28°F hard freeze is November 17 (1991–2020 NOAA normals), and it can strike as early as October 22 — so winterize your RV in Corvallis by November 7. It's a short step from frost to a hard freeze: roughly 20 days on average.

OUTLOOK

Typical first first 28°F freeze near Nov 17; local deadline about Nov 7. The live 10-day outlook loads here.

Local freeze dates for Corvallis

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Oct 5Oct 28Nov 19
28°F (hard freeze)Oct 22Nov 17Dec 18
24°F (severe)Nov 7Dec 5Jan 13

NOAA station: Corvallis State Univ · 6.0 mi away · 225 ft elevation.

Corvallis draws its numbers from Corvallis State Univ, 225 feet up and 6.0 miles away. Its median first-freeze dates are 32°F by Oct 28, 28°F by Nov 17, 24°F by Dec 5. The 28°F freeze has come as early as Oct 22 and as late as Dec 18, a 57-day spread. Spring's last 32°F freeze clears around Apr 17. Snowfall averages 3 inches a year.

Expect the first frost near Oct 28 in Corvallis and the first hard freeze by about Nov 17. Year to year, the first 32°F night has fallen anywhere from Oct 5 to Nov 19 — about 45 days apart. Spring's final freeze lands near Apr 17 and as late as May 8, so that is when outdoor water and stored gear can safely come back online. Measurable snow is rare, so the freeze near Apr 17 — 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, Corvallis (first freeze Nov 17) runs close to Albany (Nov 17) and about a week ahead of Salem (Nov 22). Across Oregon, local prep deadlines in our data range from Sep 24 to Dec 11, so a statewide rule of thumb would miss Corvallis by weeks. In Corvallis, that same cold is your cue to shut down your sprinklers and winterize a boat.

Other winter jobs in Corvallis

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

Sprinklers → Nov 7Frozen pipes → Oct 5Car battery → Nov 17Sump pump → Apr 17Boat → Nov 10Motorcycle → Oct 28

See the full Corvallis 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 Corvallis?
Wait until the last spring freeze has passed, which averages near Apr 17 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 Corvallis State Univ, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.