A North Shore power outage in January is not the same problem as one in July. Once the furnace stops, a home starts losing heat right away, and pipes can freeze in a matter of hours if nobody catches it in time. The best defense is getting ready before the first cold snap, not during it. This guide walks through what to check on your ComEd account, your Nicor or North Shore Gas furnace, and your pipes, so a winter outage in Evanston, Wilmette, Winnetka, or any other North Shore town costs you a cold night instead of a flooded basement.
How Cold a North Shore Winter Gets
The North Shore averages a high near 29 degrees and a low near 15 degrees in January, based on National Weather Service data for O'Hare. Chicago's coldest day on record hit minus 27 degrees on January 20, 1985, with a wind chill near minus 57 degrees. Numbers like that are cold enough to freeze an exposed pipe fast once the furnace stops running.
Winter weather on the lake tends to run from November through March, with the sharpest cold snaps usually landing in January and February. A storm that knocks down a tree limb onto a ComEd line does not care what season it is, but a summer outage is an inconvenience while a winter outage can turn into a plumbing emergency within a few hours. That is why this checklist exists separately from a general post storm outage checklist, which covers what to do the moment the lights go out any time of year.
How Long Before Your Pipes Freeze Without Power
A home with the heat running typically holds enough warmth to keep indoor air above 55 degrees for three to five hours after the power goes out, and pipes are usually safe as long as the house stays above that line. Once the temperature drops further, exposed pipes in a garage, crawlspace, or exterior wall are the first to go. The table below is a general guide, not a guarantee, since insulation, wind, and how long the furnace already ran before the outage all change the math.
| Outside Temperature | Time Home Stays Above 55°F | Risk to Exposed Pipes |
|---|---|---|
| 20°F to 32°F | Around 5 to 8 hours | Low if power returns the same day |
| 0°F to 20°F | Around 3 to 5 hours | Pipes on exterior walls at risk |
| Below 0°F | Around 2 to 3 hours | High. Act fast, drain what you can |
Frozen and burst pipes are not a small claim, either. The average U.S. household claim for water damage and freezing runs about $12,514, and water damage of this kind makes up nearly a quarter of all homeowners insurance claims, according to Insurance Information Institute data. Knowing your shutoff valve and keeping a slow drip going in a long outage is a lot cheaper than a repair bill. For a closer look at exactly how many hours you have before pipes are at risk, see our hour by hour pipe freeze timeline.
Winterize Your Home Before the First Cold Snap
Most winter outage damage traces back to prep work that never got done. Work through this list before the temperature drops, not after the forecast turns bad.
- Know where your main water shutoff valve is, and make sure everyone in the house does too.
- Insulate exposed pipes in the garage, attic, and crawlspace with foam sleeves. It is a cheap fix that pays for itself the first time you need it.
- Caulk and weatherstrip drafty doors and windows. A leaky house loses its heat reserve faster once the furnace shuts off.
- Have your furnace serviced before the season starts, and check that your Nicor or North Shore Gas meter and vents are clear of snow and debris.
- Test carbon monoxide and smoke detectors, and make sure at least one of each has battery backup so it still works with the power out.
- Clear gutters before the first freeze. Ice dams from clogged gutters can force water back under the roofline during a thaw.
Your Sump Pump and the Winter Thaw
Winter outages on the North Shore often show up with the same weather pattern: a fast moving storm that brings rain and wind on top of snow already on the ground, followed by a quick thaw. That combination sends meltwater into the ground right when a sump pump is working hardest, and a sump pump that loses power during a thaw stops just as fast as one that loses power during a summer downpour. Older homes in Evanston and Wilmette with combined sewer connections are especially exposed, since backups there are not just a nuisance but a basement full of water.
A battery backup sump pump system, or a whole home standby generator, keeps that pump running through the outage instead of leaving it silent during the exact hours it matters most.
Not Sure Your Home Is Ready for a Multi Day Winter Outage?
A licensed and insured electrician can walk your home and tell you what a standby generator would cost to protect your furnace, sump pump, and fridge.
Request a QuoteBuild a Winter Power Outage Kit
Keep this stocked in one spot, like a front hall closet, so nobody is digging through the garage in the dark.
- Water and shelf stable food for at least three days, plus a manual can opener.
- Flashlights and headlamps with fresh batteries. Skip the candles where you can, since they are a leading cause of house fires during outages.
- Extra blankets and warm layers for every person and pet in the house.
- A battery bank or car charger to keep phones charged for outage updates and reporting.
- A list of any medical equipment in the house that runs on electricity, like a CPAP machine, oxygen concentrator, or home dialysis equipment, and a plan for each one.
- Battery powered or battery backup carbon monoxide and smoke detectors, tested and ready.
Staying Warm and Safe Without Heat
The biggest risks in a winter outage are not the cold itself but the shortcuts people take to fight it. According to the FEMA Ready.gov guidance, you should never use a stove, oven, or outdoor grill to heat a home, since it builds up carbon monoxide fast in a closed space. The same goes for a portable generator, which should always run outside, well away from windows and doors, never in a garage even with the door open.
Watch for signs of hypothermia in anyone in the house, especially older adults and young kids. The CDC lists shivering, slurred speech, confusion, and clumsiness as early warning signs. If someone shows those signs, warm them up gradually and get medical help. Close off unused rooms, layer blankets over doors and windows to trap heat in one central room, and check on elderly neighbors who may not have backup heat of their own.
When the Power Comes Back On
Walk the house before you relax. Check exposed pipes in the garage, crawlspace, and basement for any sign of a slow leak that started while the heat was off. Reset breakers and check that your furnace and water heater have restarted normally, since a hard outage can sometimes trip a safety switch that needs a manual reset. Throw out any refrigerated food that sat above 40 degrees for more than two hours, and check the freezer for ice crystals that mean food is still safe. If your sump pump ran without power for any length of time, check the basement floor drain and perimeter for standing water before it becomes mold.
Frequently Asked Questions
How cold does it get on the North Shore in a typical winter?
January highs average near 29 degrees and lows average near 15 degrees at O'Hare, per National Weather Service records. Cold snaps below zero happen most winters, and Chicago's all time record low is minus 27 degrees, set on January 20, 1985.
How long can my house go without heat before pipes freeze?
Most homes hold enough warmth to stay above 55 degrees for three to five hours after losing power. Below zero, that window can shrink to two to three hours, especially for pipes on exterior walls or in unheated spaces like a garage.
Should I let my faucets drip during a winter outage?
Yes, if the outage is expected to last more than a few hours in freezing weather. A slow drip keeps water moving through the pipe, which makes it much harder to freeze solid.
Is it safe to run a portable generator in the garage during a snowstorm?
No. A portable generator should run outside, well away from windows, doors, and vents, no matter how cold or snowy it is outside. Carbon monoxide from an enclosed or partially enclosed space can be deadly within minutes.
What happens to my sump pump if the power goes out during a winter thaw?
It stops working unless it has a battery backup or the home has a standby generator. A sudden thaw on top of existing snow can send a lot of water into the ground at once, so a sump pump going silent during that window is one of the more common causes of a flooded basement.
Do I need a whole home generator just for winter outages, or is it worth it year round?
Most North Shore homeowners who install one use it for storms in every season, not just winter. If you want the full cost breakdown, see our guide to whole house generator costs in Illinois.
Winter outages are unpredictable, but your prep does not have to be. Once your pipes, sump pump, and heat source are covered, the next question is usually whether a standby generator makes sense for your home. If you would rather not find out the hard way what a multi day outage costs in frozen pipes and spoiled food, request a quote and a licensed and insured electrician will walk you through what it would take to keep your North Shore home running through the next storm.