FrostList

When to Winterize Your RV in Cary, NC

ON TRACK135 days until first 28°F freezeNov 23

Cary's median first 28°F hard freeze is November 23 (1991–2020 NOAA normals), and it can strike as early as November 6 — so winterize your RV in Cary by November 13. It's a short step from frost to a hard freeze: roughly 15 days on average.

OUTLOOK

Typical first first 28°F freeze near Nov 23; local deadline about Nov 13. The live 10-day outlook loads here.

Local freeze dates for Cary

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Oct 28Nov 8Nov 27
28°F (hard freeze)Nov 6Nov 23Dec 15
24°F (severe)Nov 18Dec 10Jan 7

NOAA station: Raleigh State Univ · 4.6 mi away · 400 ft elevation.

For Cary, the nearest NOAA station with freeze data is Raleigh State Univ, 4.6 miles out at 400 feet. Median first-freeze dates there run 32°F by Nov 8, 28°F by Nov 23, 24°F by Dec 10. That hard freeze has landed anywhere from Nov 6 to Dec 15, a swing of roughly 39 days. Spring's last 32°F freeze clears around Mar 28. Snowfall averages 4 inches a year, first reaching an inch near December.

Expect the first frost near Nov 8 in Cary and the first hard freeze by about Nov 23. Year to year, the first 32°F night has fallen anywhere from Oct 28 to Nov 27 — about 30 days apart. Spring's final freeze lands near Mar 28 and as late as Apr 12, so that is when outdoor water and stored gear can safely come back online. Snow is light here, near 4 inches a year, so pipe and battery cold usually matters more than plowing.

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

Cary freezes close to Apex (Nov 21) and close to Raleigh (Nov 23) — a reminder that even nearby towns differ by days. Statewide, North Carolina prep dates run Oct 31 through Nov 23, which is why Cary gets its own number rather than a North Carolina-wide average. The same freeze also decides when to shut down your sprinklers and winterize a boat.

Other winter jobs in Cary

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

Sprinklers → Nov 13Frozen pipes → Oct 28Ice dams → Nov 15Car battery → Nov 23Snow blower → Nov 24Sump pump → Mar 28Boat → Nov 16Motorcycle → Nov 8

See the full Cary 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 Cary?
Wait until the last spring freeze has passed, which averages near Mar 28 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 Raleigh State Univ, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.