FrostList

When to Winterize Your RV in North Charleston, SC

ON TRACK157 days until first 28°F freezeDec 15

North Charleston's deadline to winterize your RV is December 5: the local first 28°F freeze runs December 15 on average and November 21 at its earliest (1991–2020 normals). The early-odds date runs roughly 24 days ahead of the median, so build in that buffer.

OUTLOOK

Typical first first 28°F freeze near Dec 15; local deadline about Dec 5. The live 10-day outlook loads here.

Local freeze dates for North Charleston

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Nov 8Nov 27Dec 21
28°F (hard freeze)Nov 21Dec 15Jan 13
24°F (severe)Dec 4Jan 1Jan 29

NOAA station: Charleston Intl AP · 4.9 mi away · 40 ft elevation.

The reference station for North Charleston is Charleston Intl AP (4.9 mi, 40 ft). First freeze there: 32°F by Nov 27, 28°F by Dec 15, 24°F by Jan 1. The 28°F freeze has come as early as Nov 21 and as late as Jan 13, a 53-day spread. Spring's last 32°F freeze clears around Mar 7. Snowfall averages 0 inches a year.

The freeze arrives in two steps in North Charleston: 32°F around Nov 27, then a hard 28°F near Dec 15. The 32°F date swings from Nov 8 at its earliest to Dec 21 at its latest, near 43 days. The last spring freeze averages Mar 7 and as late as Mar 27, which sets the safe window for reopening outdoor water and de-winterizing gear. Snow barely registers here; the freeze date, around Mar 7, is the one that matters.

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, North Charleston (first freeze Dec 15) runs later than Charleston (Jan 8) and close to Mount Pleasant (Dec 16). Across South Carolina, local prep deadlines in our data range from Nov 1 to Dec 29, so a statewide rule of thumb would miss North Charleston by weeks. In North Charleston, that same cold is your cue to shut down your sprinklers and winterize a boat.

Other winter jobs in North Charleston

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

Sprinklers → Dec 5Frozen pipes → Nov 8Car battery → Dec 15Sump pump → Mar 7Boat → Dec 8Motorcycle → Nov 27

See the full North Charleston 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 North Charleston?
Wait until the last spring freeze has passed, which averages near Mar 7 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 Charleston Intl AP, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.