FrostList

When to Winterize Your RV in St. Joseph, MO

ON TRACK107 days until first 28°F freezeOct 26

In a typical year, winterize your RV in St. Joseph by October 16. The median first 28°F hard freeze at St. Joseph's NOAA station is October 26 (1991–2020 normals); one year in ten it arrives as early as October 13. Plan for the early end: the one-in-ten date lands about 13 days before the median.

OUTLOOK

Typical first first 28°F freeze near Oct 26; local deadline about Oct 16. The live 10-day outlook loads here.

Local freeze dates for St. Joseph

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Sep 30Oct 17Oct 30
28°F (hard freeze)Oct 13Oct 26Nov 8
24°F (severe)Oct 23Nov 5Nov 20

NOAA station: St Joseph Rosecrans AP · 4.1 mi away · 818 ft elevation.

St. Joseph draws its numbers from St Joseph Rosecrans AP, 818 feet up and 4.1 miles away. Its median first-freeze dates are 32°F by Oct 17, 28°F by Oct 26, 24°F by Nov 5. Year to year the 28°F date has ranged from Oct 13 to Nov 8 — about 26 days apart. Spring's last 32°F freeze clears around Apr 19. Snowfall averages 21 inches a year, first reaching an inch near November.

Expect the first frost near Oct 17 in St. Joseph and the first hard freeze by about Oct 26. That first freezing night has ranged from Sep 30 to Oct 30, roughly a 30-day spread. On the spring side, the last 32°F freeze clears around Apr 19 and as late as May 3 — the green light for reopening water and de-winterizing. With around 21 inches of snow annually, plan for a handful of plowable storms each winter.

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, St. Joseph (first freeze Oct 26) runs about a week ahead of Kansas City (Nov 11) and about a week ahead of Kansas City (Nov 11). Across Missouri, local prep deadlines in our data range from Oct 16 to Nov 5, so a statewide rule of thumb would miss St. Joseph by weeks. In St. Joseph, that same cold is your cue to shut down your sprinklers and winterize a boat.

Other winter jobs in St. Joseph

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

Sprinklers → Oct 16Frozen pipes → Sep 30Ice dams → Oct 16Car battery → Oct 26Snow blower → Oct 25Sump pump → Apr 19Boat → Oct 19Motorcycle → Oct 17

See the full St. Joseph 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 St. Joseph?
Wait until the last spring freeze has passed, which averages near Apr 19 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 St Joseph Rosecrans AP, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.