How cold did the Midwest get in the polar vortex of January 2019? Cold enough to break records that had stood for decades. On the morning of 30 January, Chicago's O'Hare Airport fell to −23 °F (−31 °C), the city's coldest temperature in 34 years, with a wind chill of −52 °F. The next day Rockford, Illinois, set an all-time record of −31 °F, and in northern Minnesota the village of Cotton reported −56 °F (−49 °C).
Schools and businesses closed, thousands of flights were cancelled, and the US Postal Service suspended mail delivery in much of Michigan. At least 22 deaths were linked to the cold across the region. Yet many people still stepped outside, briefly, to photograph what extreme cold does to ordinary things: bubbles that freeze in mid-air, noodles that stand up on their own, a lake turned to a field of ice.
Below are 30 of those photos, grouped by theme, with an explanation of what is happening in each and why. We end with what the polar vortex really is and how to stay safe in this kind of cold.
Frozen lakes, rivers and shorelines
Lake Michigan from the air
Taken from one of the few flights landing in Chicago that morning, this photo shows Lake Michigan covered in broken ice, with the city skyline along the shore. The wispy haze over the water is sea smoke, or steam fog: very cold air moving over slightly warmer water makes the moisture above it condense into low fog. The scene looks more like the Arctic than a big American city.
Icicle curtain on Chicago's lakefront
Waves from Lake Michigan splashed onto a lakefront fence and froze instantly, building a wall of long icicles, with the John Hancock Center and other towers in the background. The person who shared it compared it to the disaster film The Day After Tomorrow. Spray ice like this forms when water hits surfaces that are far below freezing.
The Detroit River packed with ice
Seen from a high-rise in Detroit, the river separating the United States from Windsor, Canada, is filled with ice from bank to bank. The Detroit River flows fast, so it rarely freezes solid; what you see is mostly drifting pack ice. Michigan's governor declared a state of emergency during the cold wave.
Ice in places it shouldn't be
A perfect ice mould of a wheel
After two days of freezing rain, a layer of ice formed over this car's wheel and hubcap. When it cracked away, it kept the exact shape of the rim and tyre tread. Freezing rain falls as liquid and freezes on contact with cold surfaces, which is why it coats everything so evenly.
A toilet tank that froze and burst
In Minnesota, the water in this toilet tank froze into a solid block and cracked the porcelain away, leaving the ice standing on its own with the fill valve still attached. Water expands by about 9% when it turns to ice, which is also why unheated pipes burst. It is a reminder to keep heat on in every room with plumbing.
A car door that left its ice behind
This car in Chicago was coated in a thick shell of ice. When the rear door was opened, the ice stayed put, keeping the door's outline like a glass sculpture. Before driving a car like this, clear all the ice: chunks flying off a moving car can hurt other drivers.
A frozen toilet in Wisconsin
This toilet, apparently on an unheated porch or cabin, has frozen into a ring of frost crystals around a dark hole of ice. Moisture in the bowl turned into delicate frost feathers. In places like this, people often drain plumbing completely for winter.
Inside doors coated with frost
These are the inside of a set of exit doors, coated with frost and ice along the edges. Warm, humid indoor air touched the freezing metal and glass and deposited its moisture as frost. Gaps in the seals let in cold air, which is why the thickest ice is along the edges.
Frost on the toilet paper in an outhouse
In an outdoor toilet, a roll of paper is covered in a fuzz of frost crystals called hoar frost. It forms when water vapour turns straight into ice on a very cold surface, without becoming liquid first. Beautiful to look at, less pleasant to use.
A house freezing from the inside
Frost has formed along the floorboards in the corner of this room, where two outside walls meet. Corners and floors are usually the coldest parts of a room, especially in older, poorly insulated houses. Frost indoors is a sign that pipes in those walls could also be at risk.
An exhaust pipe that froze its own water
Burning fuel produces water vapour, which is why exhausts drip on cold mornings. In this cold, the water froze as it dripped, building a column and a spreading puddle of ice under the car. Never warm up a car in a closed garage: exhaust contains carbon monoxide, which can kill.
Heating a flat with the stove
A tenant in Minnesota said the landlord turned down the heating as temperatures reached −40, so they switched on all the electric hob rings and a box fan. It makes a good joke, but cooking appliances are not safe heaters and can start fires; gas ovens can also produce carbon monoxide. If your home heating fails, contact the landlord or local authorities and use a warming centre if needed.
Backyard and kitchen experiments
Bubbles that freeze in the air
When it is cold enough, a soap bubble begins to freeze the moment it is blown. Ice crystals spread across the thin film and turn the bubble into a fragile, frosted sphere. This is one of the most popular cold-weather experiments for children, as long as they stay outside only briefly.
Frozen bubbles on a patio cushion
These bubbles landed on an outdoor cushion and froze solid before they could pop, leaving clear ice spheres. Some have already cracked open. Because the soap film is so thin, it freezes in seconds in extreme cold.
Noodles that froze mid-bite
A bowl of cooked noodles left on a Chicago balcony froze with the fork lifting them in mid-air. Wet food freezes fast in such cold, especially in thin strands. It became one of the best-known images of the cold wave.
Turning hot water into snow
Throwing a pot of very hot water into air of about −40 makes an instant cloud of vapour and ice crystals. Hot water evaporates quickly into tiny droplets, which freeze before they hit the ground. Be careful: people have scalded themselves trying this, especially when the wind blows the water back.
Antifreeze that froze
In Iowa, this jug of pink RV and marine antifreeze froze at a construction site. The low numbers on these products typically refer to burst protection, the point at which they still won't crack pipes, while the liquid itself can turn to slush at much milder temperatures. Even so, it shows how unusual the cold was.
Eggs frozen inside their shells
Eggs from a backyard coop froze solid, and when peeled they looked like little glass balls with yellow centres. Freezing usually cracks the shell, because the contents expand. Cracked frozen eggs should be thrown away, as bacteria can get in.
Vodka turning to slush
A bottle of vodka left outside turned partly to ice. Vodka at 40% alcohol is commonly said to freeze at around −27 °C (about −16 °F), which matches the poster's note. In a home freezer it stays liquid; it took a polar vortex to change that.
Jeans that stand on their own
In Minnesota, someone wet a pair of jeans and left them outside, where they froze stiff and stood up in the snow like an invisible person. It is a cheerful prank that many people repeated that week. It also shows why wet clothing is dangerous in the cold: it freezes and draws heat from the body fast.
People and services working through the cold
A firefighter covered in ice
After fighting a fire in temperatures around −40, this firefighter's helmet, mask and gear were covered in ice. Spray from the hoses freezes on everything it touches. Firefighters in such weather work in shorter rotations and warm up in buses or vehicles between shifts.
A fire chief after a house fire
Another firefighter, identified in the original post as Chief Mitch Hansen, stands frosted from head to toe after a house fire south of Cameron. His beard and moustache are full of ice from the hose spray. His colleagues joked that he had mistaken the scene for a splash park.
Fire on Chicago's rail lines
The flames along these Metra tracks are not an accident. They come from gas-fired switch heaters, which keep snow and ice out of the moving parts of track switches so trains can change lines. In extreme cold, the heaters run constantly and the flames are easy to see.
A frozen sheriff's uniform
Officers at the Chisago County Sheriff's Office in Minnesota posted this photo of a uniform shirt and trousers frozen stiff enough to stand next to a patrol car. It was a light-hearted post during a hard week for police and rescue workers. It also made people smile while urging them to stay home.
Remember people without a home
This photo of a person wrapped in a blanket on a snowy bench was shared with a call to support local homeless shelters, many of which were full. In extreme cold, people sleeping outside face the highest risk of hypothermia and frostbite. Cities opened warming centres, and donations of blankets, hats and gloves were badly needed.
Dressed for daycare at −30
This toddler is ready for the trip to daycare with a chunky knitted hat, a face scarf, a padded jacket and mittens. Small children lose heat faster than adults, so covering every bit of skin matters. Layers work better than one thick garment.
Wet hair that freezes in seconds
In Iowa, a young woman stepped out with wet hair, and it froze into stiff strands that stood up as she flipped it. It is a popular demonstration of how cold it is, but going out with wet hair in such weather is not a good idea, since it pulls heat from your head quickly.
Frosted eyelashes after a run
A winter runner's breath and sweat froze on her eyelashes and eyebrows, turning them white. Runners who train in such cold cover their faces and keep runs short. Frost on the skin is a warning sign that frostbite is not far away.
A "shivering" light pole in Cadillac, Michigan
Video from Cadillac, Michigan, showed a tall parking-lot light pole swaying back and forth, which people joked was shivering. The movement is caused by strong winds, which can make tall, slender poles vibrate. The cold just made it a better joke.
Measuring snow in Madison with a flamingo
The Madison football club Forward Madison FC measured the snow at its stadium with a pink plastic flamingo: half a flamingo on 25 January, nearly one whole "Mingo" by 28 January, and finally a flamingo almost completely buried. The flamingo is the club's mascot. It is a fun way to show how much snow fell in just a few days.
What the polar vortex is, and what it isn't
The polar vortex is a large area of cold, swirling air over each pole. Scientists distinguish two layers: a stratospheric vortex, roughly 15 to 50 km up, and a lower tropospheric one bounded by the jet stream. Both are strongest in winter.
When the vortex weakens or splits, often after a sudden warming high in the stratosphere, the jet stream can bend far south and let Arctic air pour into the mid-latitudes. That is what happened in late January 2019: a lobe of the vortex stalled over central Canada and the north-central United States. Strictly speaking, the vortex itself did not "arrive" in Chicago; its Arctic air did.
Is climate change making these outbreaks more common? Scientists are still debating it. One hypothesis says a warming Arctic weakens the jet stream and makes cold snaps more likely, while other studies find the effect small compared with natural variation. What is clear is that a cold week does not disprove global warming, and a warm one does not prove it; climate is measured over decades.
How to stay safe in extreme cold
- Watch the wind chill, not just the temperature. Wind makes skin lose heat much faster. According to the US National Weather Service, even a wind chill of −19 °F can cause frostbite on exposed skin in about 30 minutes; at −50 it happens far faster.
- Cover every bit of skin and dress in layers, with a hat, scarf over the face and mittens rather than gloves.
- Know the warning signs. Numb, white or greyish skin can signal frostbite; shivering, confusion and slurred speech can signal hypothermia. Get indoors and talk to a doctor or call emergency services.
- Heat safely. Never use ovens, hobs, grills or generators indoors to heat a home, and keep a working carbon monoxide alarm.
- Protect pipes by keeping the heating on, opening cupboard doors under sinks and letting taps drip.
- Check on others, especially older neighbours and anyone sleeping outdoors, and bring pets inside.
The photos from 2019 are fun to look at, but behind them was a deadly week. The best response to a cold wave is to enjoy it through the window when you can, and to look out for the people who can't.
Sources: Photo credits under each image. Facts: National Weather Service Chicago: Record cold, January 2019; National Weather Service: Wind chill chart; Wikipedia: January–February 2019 North American cold wave, Polar vortex, Sea smoke.
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