FrostList

When to Winterize Your RV in Centennial, CO

ON TRACK98 days until first 28°F freezeOct 17

Aim to winterize your RV in Centennial by October 7, roughly a week and a half before the median first 28°F freeze of October 17, which one fall in ten shows up by October 4. The early-odds date runs roughly 13 days ahead of the median, so build in that buffer.

OUTLOOK

Typical first first 28°F freeze near Oct 17; local deadline about Oct 7. The live 10-day outlook loads here.

Local freeze dates for Centennial

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Sep 25Oct 8Oct 20
28°F (hard freeze)Oct 4Oct 17Oct 28
24°F (severe)Oct 13Oct 26Nov 10

NOAA station: Denver Centennial AP · 1.7 mi away · 5,883 ft elevation.

The reference station for Centennial is Denver Centennial AP (1.7 mi, 5,883 ft). First freeze there: 32°F by Oct 8, 28°F by Oct 17, 24°F by Oct 26. The 28°F freeze has come as early as Oct 4 and as late as Oct 28, a 24-day spread. Spring's last 32°F freeze clears around May 5. Snowfall averages 34 inches a year, first reaching an inch near October.

In Centennial, freezing nights (32°F) typically begin around Oct 8 and the first hard freeze (28°F) follows near Oct 17. That first freezing night has ranged from Sep 25 to Oct 20, roughly a 25-day spread. On the spring side, the last 32°F freeze clears around May 5 and as late as May 17 — the green light for reopening water and de-winterizing. With around 34 inches of snow annually, plan for a handful of plowable storms each winter.

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, Centennial (first freeze Oct 17) runs later than Parker (Oct 12) and about a week ahead of Littleton (Oct 21). Across Colorado, local prep deadlines in our data range from Sep 30 to Oct 23, so a statewide rule of thumb would miss Centennial by weeks. In Centennial, that same cold is your cue to shut down your sprinklers and winterize a boat.

Other winter jobs in Centennial

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

Sprinklers → Oct 7Frozen pipes → Sep 25Ice dams → Sep 15Car battery → Oct 17Snow blower → Sep 24Sump pump → May 5Boat → Oct 10Motorcycle → Oct 8

See the full Centennial 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 Centennial?
Wait until the last spring freeze has passed, which averages near May 5 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 Denver Centennial AP, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.