FrostList

When to Winterize Your RV in Wausau, WI

ON TRACK97 days until first 28°F freezeOct 16

Aim to winterize your RV in Wausau by October 6, roughly a week and a half before the median first 28°F freeze of October 16, which one fall in ten shows up by October 1. Cold deepens quickly here — only about 12 days separate the first frost from that hard freeze.

OUTLOOK

Typical first first 28°F freeze near Oct 16; local deadline about Oct 6. The live 10-day outlook loads here.

Local freeze dates for Wausau

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Sep 21Oct 4Oct 18
28°F (hard freeze)Oct 1Oct 16Oct 31
24°F (severe)Oct 14Oct 30Nov 13

NOAA station: Wausau Dwtn AP · 2.3 mi away · 1,181 ft elevation.

Wausau draws its numbers from Wausau Dwtn AP, 1,181 feet up and 2.3 miles away. Its median first-freeze dates are 32°F by Oct 4, 28°F by Oct 16, 24°F by Oct 30. The 28°F freeze has come as early as Oct 1 and as late as Oct 31, a 30-day spread. Spring's last 32°F freeze clears around May 6. Snowfall averages 64 inches a year, first reaching an inch near November.

In Wausau, freezing nights (32°F) typically begin around Oct 4 and the first hard freeze (28°F) follows near Oct 16. That first freezing night has ranged from Sep 21 to Oct 18, roughly a 27-day spread. On the spring side, the last 32°F freeze clears around May 6 and as late as May 21 — the green light for reopening water and de-winterizing. Snow totals near 64 inches a year mean plowing and ice-dam control share the winter to-do list here.

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, Wausau (first freeze Oct 16) runs close to Appleton (Oct 18) and about a week ahead of Oshkosh (Oct 31). Across Wisconsin, local prep deadlines in our data range from Oct 6 to Oct 27, so a statewide rule of thumb would miss Wausau by weeks. In Wausau, that same cold is your cue to shut down your sprinklers and winterize a boat.

Other winter jobs in Wausau

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

Sprinklers → Oct 6Frozen pipes → Sep 21Ice dams → Oct 16Car battery → Oct 16Snow blower → Oct 25Sump pump → May 6Boat → Oct 9Motorcycle → Oct 4

See the full Wausau 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 Wausau?
Wait until the last spring freeze has passed, which averages near May 6 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 Wausau Dwtn AP, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.