FrostList

When to Winterize Your RV in Berwyn, IL

ON TRACK123 days until first 28°F freezeNov 11

In a typical year, winterize your RV in Berwyn by November 1. The median first 28°F hard freeze at Berwyn's NOAA station is November 11 (1991–2020 normals); one year in ten it arrives as early as October 31. Cold deepens quickly here — only about 11 days separate the first frost from that hard freeze.

OUTLOOK

Typical first first 28°F freeze near Nov 11; local deadline about Nov 1. The live 10-day outlook loads here.

Local freeze dates for Berwyn

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Oct 20Oct 31Nov 14
28°F (hard freeze)Oct 31Nov 11Nov 26
24°F (severe)Nov 7Nov 20Dec 5

NOAA station: Chicago Midway AP · 4.9 mi away · 612 ft elevation.

Berwyn draws its numbers from Chicago Midway AP, 612 feet up and 4.9 miles away. Its median first-freeze dates are 32°F by Oct 31, 28°F by Nov 11, 24°F by Nov 20. Year to year the 28°F date has ranged from Oct 31 to Nov 26 — about 26 days apart. Spring's last 32°F freeze clears around Apr 11. Snowfall averages 39 inches a year, first reaching an inch near November.

The freeze arrives in two steps in Berwyn: 32°F around Oct 31, then a hard 28°F near Nov 11. That first freezing night has ranged from Oct 20 to Nov 14, roughly a 25-day spread. On the spring side, the last 32°F freeze clears around Apr 11 and as late as Apr 27 — the green light for reopening water and de-winterizing. With around 39 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

Compared with nearby cities, Berwyn's first-freeze date near Nov 11 sits close to Cicero (Nov 11) and close to Oak Park (Nov 11). Illinois's deadlines span Oct 14 to Nov 5 statewide — one date for all of Illinois would be off by weeks for Berwyn. Once you know Berwyn's freeze date, use it to shut down your sprinklers and winterize a boat too.

Other winter jobs in Berwyn

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

Sprinklers → Nov 1Frozen pipes → Oct 20Ice dams → Oct 16Car battery → Nov 11Snow blower → Oct 25Sump pump → Apr 11Boat → Nov 4Motorcycle → Oct 31

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