FrostList

When to Winterize Your RV in Maricopa, AZ

ON TRACK148 days until first 28°F freezeDec 6

In a typical year, winterize your RV in Maricopa by November 26. The median first 28°F hard freeze at Maricopa's NOAA station is December 6 (1991–2020 normals); one year in ten it arrives as early as November 21. It's a short step from frost to a hard freeze: roughly 12 days on average.

OUTLOOK

Typical first first 28°F freeze near Dec 6; local deadline about Nov 26. The live 10-day outlook loads here.

Local freeze dates for Maricopa

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Nov 10Nov 24Dec 8
28°F (hard freeze)Nov 21Dec 6Dec 23
24°F (severe)Dec 1Dec 18Jan 14

NOAA station: Maricopa 4 N · 4.0 mi away · 1,160 ft elevation.

Numbers for Maricopa come from Maricopa 4 N, 4.0 miles away at 1,160 feet, where the medians fall 32°F by Nov 24, 28°F by Dec 6, 24°F by Dec 18. The 28°F freeze has come as early as Nov 21 and as late as Dec 23, a 32-day spread. Spring's last 32°F freeze clears around Feb 23.

Expect the first frost near Nov 24 in Maricopa and the first hard freeze by about Dec 6. Year to year, the first 32°F night has fallen anywhere from Nov 10 to Dec 8 — about 28 days apart. Spring's final freeze lands near Feb 23 and as late as Mar 15, so that is when outdoor water and stored gear can safely come back online. Measurable snow is rare, so the freeze near Feb 23 — not snow load — drives the local prep list.

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

Maricopa freezes about a week ahead of Casa Grande (Dec 22) and about a week ahead of Tempe (Dec 19) — a reminder that even nearby towns differ by days. Statewide, Arizona prep dates run Sep 29 through Dec 25, which is why Maricopa gets its own number rather than a Arizona-wide average. The same freeze also decides when to shut down your sprinklers and winterize a boat.

Other winter jobs in Maricopa

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

Sprinklers → Nov 26Frozen pipes → Nov 10Car battery → Dec 6Sump pump → Feb 23Boat → Nov 29Motorcycle → Nov 24

See the full Maricopa 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 Maricopa?
Wait until the last spring freeze has passed, which averages near Feb 23 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 Maricopa 4 N, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.