FrostList

When to Winterize Your RV in Parker, CO

ON TRACK93 days until first 28°F freezeOct 12

In a typical year, winterize your RV in Parker by October 2. The median first 28°F hard freeze at Parker's NOAA station is October 12 (1991–2020 normals); one year in ten it arrives as early as September 29. With about a 24-day spread, the date holds fairly steady from year to year.

OUTLOOK

Typical first first 28°F freeze near Oct 12; local deadline about Oct 2. The live 10-day outlook loads here.

Local freeze dates for Parker

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Sep 21Oct 3Oct 15
28°F (hard freeze)Sep 29Oct 12Oct 23
24°F (severe)Oct 6Oct 20Nov 2

NOAA station: Parker · 0.7 mi away · 5,904 ft elevation.

Numbers for Parker come from Parker, 0.7 miles away at 5,904 feet, where the medians fall 32°F by Oct 3, 28°F by Oct 12, 24°F by Oct 20. Year to year the 28°F date has ranged from Sep 29 to Oct 23 — about 24 days apart. Spring's last 32°F freeze clears around May 9. Snowfall averages 58 inches a year, first reaching an inch near October.

Expect the first frost near Oct 3 in Parker and the first hard freeze by about Oct 12. The 32°F date swings from Sep 21 at its earliest to Oct 15 at its latest, near 24 days. The last spring freeze averages May 9 and as late as May 23, which sets the safe window for reopening outdoor water and de-winterizing gear. Roughly 58 inches of snow fall in an average year, so a clear roof edge and a running snow blower matter as much as the freeze itself.

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, Parker (first freeze Oct 12) runs about a week ahead of Centennial (Oct 17) and close to Castle Rock (Oct 12). Across Colorado, local prep deadlines in our data range from Sep 30 to Oct 23, so a statewide rule of thumb would miss Parker by weeks. In Parker, that same cold is your cue to shut down your sprinklers and winterize a boat.

Other winter jobs in Parker

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

Sprinklers → Oct 2Frozen pipes → Sep 21Ice dams → Sep 15Car battery → Oct 12Snow blower → Sep 24Sump pump → May 9Boat → Oct 5Motorcycle → Oct 3

See the full Parker 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 Parker?
Wait until the last spring freeze has passed, which averages near May 9 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 Parker, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.