FrostList

When to Winterize Your RV in Chico, CA

ON TRACK145 days until first 28°F freezeDec 3

Chico's deadline to winterize your RV is November 23: the local first 28°F freeze runs December 3 on average and November 13 at its earliest (1991–2020 normals). The early-to-late range spans roughly 53 days, so treat the median as a midpoint, not a promise.

OUTLOOK

Typical first first 28°F freeze near Dec 3; local deadline about Nov 23. The live 10-day outlook loads here.

Local freeze dates for Chico

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Nov 1Nov 17Dec 5
28°F (hard freeze)Nov 13Dec 3Jan 5
24°F (severe)Nov 28Dec 22Jan 18

NOAA station: Chico Univ Farm · 2.7 mi away · 185 ft elevation.

Numbers for Chico come from Chico Univ Farm, 2.7 miles away at 185 feet, where the medians fall 32°F by Nov 17, 28°F by Dec 3, 24°F by Dec 22. That hard freeze has landed anywhere from Nov 13 to Jan 5, a swing of roughly 53 days. Spring's last 32°F freeze clears around Mar 4. Snowfall averages 0 inches a year.

Expect the first frost near Nov 17 in Chico and the first hard freeze by about Dec 3. The 32°F date swings from Nov 1 at its earliest to Dec 5 at its latest, near 34 days. The last spring freeze averages Mar 4 and as late as Apr 2, which sets the safe window for reopening outdoor water and de-winterizing gear. Snow barely registers here; the freeze date, around Mar 4, 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

Chico freezes about a week ahead of Yuba City (Dec 24) and about a week ahead of Lincoln (Dec 22) — a reminder that even nearby towns differ by days. Statewide, California prep dates run Jan 6 through Dec 27, which is why Chico 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 Chico

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

Sprinklers → Nov 23Frozen pipes → Nov 1Car battery → Dec 3Sump pump → Mar 4Boat → Nov 26Motorcycle → Nov 17

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