FrostList

When to Winterize Your RV in Plymouth, MN

ON TRACK103 days until first 28°F freezeOct 22

Aim to winterize your RV in Plymouth by October 12, roughly a week and a half before the median first 28°F freeze of October 22, which one fall in ten shows up by October 8. Cold deepens quickly here — only about 10 days separate the first frost from that hard freeze.

OUTLOOK

Typical first first 28°F freeze near Oct 22; local deadline about Oct 12. The live 10-day outlook loads here.

Local freeze dates for Plymouth

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Sep 29Oct 12Oct 25
28°F (hard freeze)Oct 8Oct 22Nov 4
24°F (severe)Oct 19Nov 1Nov 14

NOAA station: New Hope · 3.7 mi away · 910 ft elevation.

Numbers for Plymouth come from New Hope, 3.7 miles away at 910 feet, where the medians fall 32°F by Oct 12, 28°F by Oct 22, 24°F by Nov 1. Year to year the 28°F date has ranged from Oct 8 to Nov 4 — about 27 days apart. Spring's last 32°F freeze clears around Apr 29. Snowfall averages 54 inches a year, first reaching an inch near November.

The freeze arrives in two steps in Plymouth: 32°F around Oct 12, then a hard 28°F near Oct 22. That first freezing night has ranged from Sep 29 to Oct 25, roughly a 26-day spread. On the spring side, the last 32°F freeze clears around Apr 29 and as late as May 12 — the green light for reopening water and de-winterizing. Snow totals near 54 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

Compared with nearby cities, Plymouth's first-freeze date near Oct 22 sits later than Maple Grove (Oct 18) and close to St. Louis Park (Oct 22). Minnesota's deadlines span Sep 28 to Oct 19 statewide — one date for all of Minnesota would be off by weeks for Plymouth. Once you know Plymouth's freeze date, use it to shut down your sprinklers and winterize a boat too.

Other winter jobs in Plymouth

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

Sprinklers → Oct 12Frozen pipes → Sep 29Ice dams → Oct 16Car battery → Oct 22Snow blower → Oct 25Sump pump → Apr 29Boat → Oct 15Motorcycle → Oct 12

See the full Plymouth 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 Plymouth?
Wait until the last spring freeze has passed, which averages near Apr 29 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 New Hope, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.