FrostList

When to Winterize Your RV in Greeley, CO

ON TRACK99 days until first 28°F freezeOct 18

In a typical year, winterize your RV in Greeley by October 8. The median first 28°F hard freeze at Greeley's NOAA station is October 18 (1991–2020 normals); one year in ten it arrives as early as October 4. At about 4,715 feet, valley cold can run a few degrees ahead of the station reading.

OUTLOOK

Typical first first 28°F freeze near Oct 18; local deadline about Oct 8. The live 10-day outlook loads here.

Local freeze dates for Greeley

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Sep 26Oct 8Oct 21
28°F (hard freeze)Oct 4Oct 18Nov 1
24°F (severe)Oct 13Oct 28Nov 10

NOAA station: Greeley Unc · 1.5 mi away · 4,715 ft elevation.

The reference station for Greeley is Greeley Unc (1.5 mi, 4,715 ft). First freeze there: 32°F by Oct 8, 28°F by Oct 18, 24°F by Oct 28. Year to year the 28°F date has ranged from Oct 4 to Nov 1 — about 28 days apart. Spring's last 32°F freeze clears around May 2. Snowfall averages 35 inches a year, first reaching an inch near October.

Greeley usually sees its first 32°F night about Oct 8, with the first 28°F hard freeze close behind near Oct 18. That first freezing night has ranged from Sep 26 to Oct 21, roughly a 25-day spread. On the spring side, the last 32°F freeze clears around May 2 and as late as May 14 — the green light for reopening water and de-winterizing. With around 35 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

Greeley freezes later than Loveland (Oct 10) and close to Fort Collins (Oct 17) — a reminder that even nearby towns differ by days. Statewide, Colorado prep dates run Sep 30 through Oct 23, which is why Greeley gets its own number rather than a Colorado-wide average. The same freeze also decides when to shut down your sprinklers and winterize a boat.

Other winter jobs in Greeley

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

Sprinklers → Oct 8Frozen pipes → Sep 26Ice dams → Sep 15Car battery → Oct 18Snow blower → Sep 24Sump pump → May 2Boat → Oct 11Motorcycle → Oct 8

See the full Greeley 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 Greeley?
Wait until the last spring freeze has passed, which averages near May 2 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 Greeley Unc, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.