FrostList

When to Winterize Your RV in Santa Rosa, CA

ON TRACK158 days until first 28°F freezeDec 16

Aim to winterize your RV in Santa Rosa by December 6, roughly a week and a half before the median first 28°F freeze of December 16, which one fall in ten shows up by November 26. Year to year the date swings about 54 days, which is why the live outlook beats the calendar.

OUTLOOK

Typical first first 28°F freeze near Dec 16; local deadline about Dec 6. The live 10-day outlook loads here.

Local freeze dates for Santa Rosa

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Nov 10Dec 1Dec 24
28°F (hard freeze)Nov 26Dec 16Jan 19
24°F (severe)Dec 3Dec 29Jan 22

NOAA station: Santa Rosa · 1.1 mi away · 166 ft elevation.

Santa Rosa draws its numbers from Santa Rosa, 166 feet up and 1.1 miles away. Its median first-freeze dates are 32°F by Dec 1, 28°F by Dec 16, 24°F by Dec 29. The 28°F freeze has come as early as Nov 26 and as late as Jan 19, a 54-day spread. Spring's last 32°F freeze clears around Feb 25.

In Santa Rosa, freezing nights (32°F) typically begin around Dec 1 and the first hard freeze (28°F) follows near Dec 16. Year to year, the first 32°F night has fallen anywhere from Nov 10 to Dec 24 — about 44 days apart. Spring's final freeze lands near Feb 25 and as late as Mar 29, so that is when outdoor water and stored gear can safely come back online. Measurable snow is rare, so the freeze near Feb 25 — 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

Against its neighbors, Santa Rosa (first freeze Dec 16) runs later than Rohnert Park (Dec 9) and later than Petaluma (Dec 9). Across California, local prep deadlines in our data range from Jan 6 to Dec 27, so a statewide rule of thumb would miss Santa Rosa by weeks. In Santa Rosa, that same cold is your cue to shut down your sprinklers and winterize a boat.

Other winter jobs in Santa Rosa

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

Sprinklers → Dec 6Frozen pipes → Nov 10Car battery → Dec 16Sump pump → Feb 25Boat → Dec 9Motorcycle → Dec 1

See the full Santa Rosa 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 Rosa?
Wait until the last spring freeze has passed, which averages near Feb 25 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 Rosa, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.