FrostList

When to Winterize Your RV in Santa Cruz, CA

ON TRACK169 days until first 28°F freezeDec 27

In a typical year, winterize your RV in Santa Cruz by December 17. The median first 28°F hard freeze at Santa Cruz's NOAA station is December 27 (1991–2020 normals); one year in ten it arrives as early as December 6. Cold deepens quickly here — only about 14 days separate the first frost from that hard freeze.

OUTLOOK

Typical first first 28°F freeze near Dec 27; local deadline about Dec 17. The live 10-day outlook loads here.

Local freeze dates for Santa Cruz

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Nov 23Dec 13Jan 22
28°F (hard freeze)Dec 6Dec 27Jan 27

NOAA station: Santa Cruz · 2.0 mi away · 70 ft elevation.

The reference station for Santa Cruz is Santa Cruz (2.0 mi, 70 ft). First freeze there: 32°F by Dec 13, 28°F by Dec 27. The 28°F freeze has come as early as Dec 6 and as late as Jan 27, a 52-day spread. Spring's last 32°F freeze clears around Jan 29.

In Santa Cruz, freezing nights (32°F) typically begin around Dec 13 and the first hard freeze (28°F) follows near Dec 27. That first freezing night has ranged from Nov 23 to Jan 22, roughly a 60-day spread. On the spring side, the last 32°F freeze clears around Jan 29 and as late as Feb 28 — the green light for reopening water and de-winterizing. With almost no snow in a normal year, cold — not plowing — sets the calendar, and it centers on Jan 29.

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

Santa Cruz freezes close to Watsonville (Dec 26) and later than Campbell (Dec 19) — a reminder that even nearby towns differ by days. Statewide, California prep dates run Jan 6 through Dec 27, which is why Santa Cruz gets its own number rather than a California-wide average. The same freeze also decides when to shut down your sprinklers and winterize a boat.

Other winter jobs in Santa Cruz

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

Sprinklers → Dec 17Frozen pipes → Nov 23Car battery → Dec 27Sump pump → Jan 29Boat → Dec 20Motorcycle → Dec 13

See the full Santa Cruz 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 Santa Cruz?
Wait until the last spring freeze has passed, which averages near Jan 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 Santa Cruz, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.