FrostList

When to Winterize Your RV in Delano, CA

ON TRACK161 days until first 28°F freezeDec 19

Delano's deadline to winterize your RV is December 9: the local first 28°F freeze runs December 19 on average and December 3 at its earliest (1991–2020 normals). The early-to-late range spans roughly 37 days, so treat the median as a midpoint, not a promise.

OUTLOOK

Typical first first 28°F freeze near Dec 19; local deadline about Dec 9. The live 10-day outlook loads here.

Local freeze dates for Delano

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Nov 23Dec 8Dec 30
28°F (hard freeze)Dec 3Dec 19Jan 9
24°F (severe)Dec 9Dec 24Jan 3

NOAA station: Delano · 0.7 mi away · 302 ft elevation.

For Delano, the nearest NOAA station with freeze data is Delano, 0.7 miles out at 302 feet. Median first-freeze dates there run 32°F by Dec 8, 28°F by Dec 19, 24°F by Dec 24. The 28°F freeze has come as early as Dec 3 and as late as Jan 9, a 37-day spread. Spring's last 32°F freeze clears around Jan 31. Snowfall averages 0 inches a year.

Delano usually sees its first 32°F night about Dec 8, with the first 28°F hard freeze close behind near Dec 19. The 32°F date swings from Nov 23 at its earliest to Dec 30 at its latest, near 37 days. The last spring freeze averages Jan 31 and as late as Mar 5, which sets the safe window for reopening outdoor water and de-winterizing gear. Snow barely registers here; the freeze date, around Jan 31, 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

Against its neighbors, Delano (first freeze Dec 19) runs about a week ahead of Porterville (Dec 23) and close to Bakersfield (Dec 20). Across California, local prep deadlines in our data range from Jan 6 to Dec 27, so a statewide rule of thumb would miss Delano by weeks. In Delano, that same cold is your cue to shut down your sprinklers and winterize a boat.

Other winter jobs in Delano

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

Sprinklers → Dec 9Frozen pipes → Nov 23Car battery → Dec 19Sump pump → Jan 31Boat → Dec 12Motorcycle → Dec 8

See the full Delano 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 Delano?
Wait until the last spring freeze has passed, which averages near Jan 31 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 Delano, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.