Winter Weather Risk in the US: How FEMA Scores It and How to Prepare

Written by Dvir · Data: FEMA National Risk Index v1.20 · Updated August 4, 2026

Winter weather is the National Risk Index’s everyday hazard — not the rare catastrophe, but the recurring snowstorms, blizzards, and freezes that shut down commerce, close airports, and send thousands of cars into ditches every year. Individual events are usually survivable and cheap by disaster standards, but they are frequent: top-ranked counties log 10–15 winter weather events in a typical year. Nationally, the NRI books roughly $550 million in expected annual loss to winter weather (hazard code WNTW) across 3,108 counties.

What counts as winter weather risk

The NRI’s winter weather hazard covers heavy snow, blizzards, and hazardous winter conditions — as distinct from cold waves (extreme temperature) and ice storms (freezing rain), which the index scores separately. The damage profile is diffuse: roof collapses under snow load, vehicle crashes (by far the biggest killer — icy-road crashes claim more lives annually than most “major” hazards), business interruption, snow-removal costs, and heart attacks from shoveling, which are a real and consistent casualty category.

The extreme end belongs to blizzards (sustained 35+ mph winds with blowing snow and near-zero visibility) and lake-effect snow, the Great Lakes phenomenon that can bury a single county under four feet while the next county gets flurries — Buffalo’s November 2022 storm dropped over 6 feet in spots.

How the NRI measures it

FEMA combines each county’s exposure (population and building value), annualized winter-storm frequency from NOAA records, and historic loss ratios into an Expected Annual Loss, scored 0–100 against every other county. High frequency across huge exposure is what tops this table — hence big cold-climate metros rather than the snowiest rural places.

Where the risk concentrates

Cook County, IL (Chicago) leads (score 100, ~15 winter events/year), with Johnson County, KS (Kansas City suburbs) beside it, then Kings County, NY (Brooklyn — modest snow totals, extraordinary exposure), El Paso County, TX (where rare snow meets an unadapted city), and El Paso County, CO (Colorado Springs, ~15 events/year). The broader high-risk map covers the Great Lakes snowbelts, the Northeast corridor, the northern Plains, and mountain counties — plus the recurring southern surprise, where an inch of ice-crusted snow paralyzes cities with no plows.

How to read your county’s score

In the snow belt, a high score reflects priced-in frequency — the risk is managed by infrastructure, and your job is the personal layer: vehicle, roof, and heat. In southern counties with elevated scores, the score is warning you that any winter event outruns local capacity: no plows, no salt, no winter tires, drivers without ice experience. Adjust expectations accordingly — the same storm is a commute in Syracuse and a shutdown in Atlanta.

What actually reduces the risk

  • Don’t drive in it — really. Most winter-weather deaths are on the road. If you must: slow down dramatically, triple following distance, and carry a car kit (blankets, water, snacks, charger, shovel, traction aid). If stranded, stay with the vehicle, run the engine sparingly, and keep the exhaust pipe clear of snow to avoid CO poisoning.
  • Shovel like it’s exercise, because it is — snow shoveling reliably triggers heart attacks in men over 45 with any cardiac history. Push rather than lift, take breaks, or hire the neighbor kid.
  • Watch the roof math: a foot of wet snow can load 20+ lbs/sq ft. Flat and low-pitch roofs, and long-span structures (porches, barns, gyms), are the collapse risk; a roof rake on accessible eaves also prevents ice dams.
  • Prevent ice dams long-term with attic insulation and ventilation — the warm-roof melt-refreeze cycle causes chronic water damage in snow country.
  • Prepare for outages: heavy wet snow snaps lines. Flashlights, charged batteries, safe backup heat, and CO detectors (repeated deliberately — every winter storm produces generator and heater CO deaths).
  • Heed the warning tiers: winter storm watch → prepare; warning → adjust plans; blizzard warning → do not travel, period.

The storms that set the benchmarks

The Blizzard of 1888 buried the Northeast under several feet of snow with hurricane-force winds and killed roughly 400 people, many of them stranded in the open or in stalled trains. Its most durable legacy is infrastructural: the paralysis of New York’s overhead telegraph and power wires and its street-level transit accelerated the push to bury utility lines and to build subways.

The Armistice Day Blizzard (November 11, 1940) killed around 145 people across the upper Midwest, including duck hunters caught in shirtsleeves by a storm nobody forecast. Temperatures fell dozens of degrees in hours behind a system the Weather Bureau’s regional structure had failed to track. The response was a reorganization of forecasting responsibility and round-the-clock operations in the Midwest — an early demonstration that this hazard is fundamentally a warning problem.

The Superstorm of March 1993 ran from the Gulf Coast to Maine, dropping snow as far south as the Florida Panhandle and closing every major airport on the East Coast at some point. It was the first major winter storm to be well forecast several days ahead, and it validated the medium-range models that now underpin every winter storm watch.

Buffalo, New York, December 2022. A blizzard over the Christmas holiday killed dozens of people in Erie County — many in vehicles or outdoors — with whiteout conditions that stopped emergency responders themselves. It came weeks after a November lake-effect event that dropped over six feet of snow on parts of the same county. Together they illustrate both faces of the hazard: the localized lake-effect burial and the wind-driven blizzard that kills.

Atlanta, January 2014 (“Snowpocalypse”). About two inches of snow stranded tens of thousands of commuters on interstates overnight, with children sleeping in schools and buses. Nobody died in large numbers, and that is somewhat lucky. It is the canonical example of the southern-surprise scenario: a trivial snowfall by northern standards, meeting a metro with no plow fleet, no salt, no winter tires, and no habit of closing early.

Season, geography, and the two failure modes

  • Season runs November through April, peaking in January and February across most of the country, with lake-effect concentrated from late November through January while the Great Lakes remain unfrozen.
  • Lake-effect snowbelts — downwind of Lakes Erie, Ontario, Michigan, and Superior — produce the country’s most extreme localized totals. Bands are narrow: one county can receive four feet while the next receives flurries, which makes county-level averages a poor guide and local forecasts essential.
  • The Northeast corridor gets nor’easters: coastal cyclones with heavy snow, wind, and coastal flooding, hitting the densest population and transportation network in the country.
  • The northern Plains and Rockies see true blizzards — moderate snowfall with sustained high wind producing zero visibility and enormous drifts, closing interstates for days.
  • The South and Pacific Northwest face the adaptation problem. An inch of snow or a light glaze in Atlanta, Dallas, Nashville, Portland, or Seattle produces impacts that would be a non-event in Minneapolis, because the plow fleets, tire choices, driver experience, and building assumptions are not there.

The National Risk Index’s ranking reflects frequency times exposure, which is why large cold-climate metros — and southern metros where rare events cause outsized loss — outrank the snowiest rural counties in the country.

Preparing the house and the vehicle

  • Insulate and ventilate the attic to stop ice dams. Ice dams are the most common chronic winter building loss: heat escaping into the attic melts snow on the roof, water runs to the cold eaves and refreezes, and the resulting dam backs water up under the shingles and into the walls. The fix is not chipping ice off the eaves — it is air-sealing and insulating the attic floor and ensuring soffit-to-ridge ventilation so the roof deck stays cold. A roof rake on accessible eaves after heavy snow is the short-term measure.
  • Know your roof’s snow load exposure. A foot of wet snow can weigh 20 pounds per square foot or more, and rain falling on an existing snowpack is the worst case. Flat and low-slope roofs, long-span structures like porches, carports, barns, and older gymnasiums, and any roof with drifting against a taller wall are where collapses happen. Clear drifts and valleys first, and never climb onto a snow-loaded roof.
  • Protect the plumbing. Insulate pipes in unheated spaces, seal exterior air leaks near plumbing runs, know where the main water shutoff is, and let faucets drip on the coldest nights. Open cabinet doors under sinks on exterior walls.
  • Service the heating system before the season and keep a clear path to the furnace vent and the gas meter; snow-blocked high-efficiency furnace vents cause both shutdowns and carbon monoxide hazards.
  • Winterize the vehicle. Winter tires — not all-season, not four-wheel drive, which helps you accelerate and does nothing for stopping — are the largest single safety improvement for driving in snow. Keep the tank at least half full, check battery health before the season, and carry a genuine car kit: blankets or a sleeping bag, water, calorie-dense food, a phone charger and power bank, a small shovel, traction aid such as sand or cat litter, an ice scraper, jumper cables, a flashlight, and a bright cloth to signal.
  • Have a heating plan for a power outage, and detectors to go with it. Carbon monoxide detectors on every level, tested, with fresh batteries. Every winter produces deaths from generators in garages, charcoal grills indoors, unvented kerosene heaters, and gas ranges used for heat. None of those are safe indoor heating.

Insurance and cost exposure

  • Snow, ice, and weight-of-snow damage are generally covered by standard homeowners policies, including roof collapse from snow load and water damage from an ice dam that gets into the structure. Coverage for the ice dam’s cause — inadequate insulation — is not.
  • Frozen pipe bursts are covered in most policies, but usually only if you took reasonable care to maintain heat. Leaving a house unheated and unattended in winter without shutting off and draining the water is the classic denied claim. If you leave for an extended period, either keep the heat on (55°F is the usual minimum) or drain the system.
  • Freezing damage to outdoor pipes, sprinkler systems, and pools is commonly excluded.
  • Flooding from snowmelt is flood, not winter weather — excluded from homeowners policies and covered only by an NFIP or private flood policy. Spring snowmelt flooding is one of the most common uninsured losses in the northern tier.
  • Debris removal and tree damage follow the same low sublimits as in other wind events.
  • Business interruption and lost wages are the largest economic cost of winter storms in aggregate, and are almost entirely uninsured for individuals.

Before, during, and after

Before. Learn the alert tiers, because they mean specific things. A winter storm watch means significant winter weather is possible in the next day or two — this is when you get supplies and adjust plans. A winter storm warning means it is expected or occurring — change your travel plans. A blizzard warning means sustained or frequent winds of 35 mph or more with falling or blowing snow reducing visibility below a quarter mile for at least three hours: do not travel, at all. An ice storm warning means damaging freezing rain. Sign up for county alerts, stock a week of food, water, and medication, and make sure phones and power banks stay charged when a storm is forecast.

During. The dominant risk is the road. Icy-road crashes kill more Americans in a typical year than most hazards in this index combined, and the single most effective intervention is not driving. If you must, slow down far more than feels necessary, triple your following distance, brake early and gently, and remember that bridges and overpasses freeze first. If you become stranded, stay with the vehicle — it is shelter and it is findable — run the engine sparingly for heat, keep a window cracked, and clear snow from the exhaust pipe before every run to avoid carbon monoxide.

Shovel carefully. Snow shoveling triggers a documented spike in heart attacks, concentrated in men over 45 with any cardiac history, because it combines heavy isometric exertion with cold-induced vasoconstriction. Push rather than lift, take frequent breaks, skip the caffeine and the big meal beforehand, and if you have any cardiac history, pay someone else to do it.

After. Check on elderly neighbors, particularly anyone without power. Clear the exhaust vents for furnaces and dryers, and dig out fire hydrants and gas meters if they are buried. Watch for ice dams forming at the eaves and for roof loads after rain-on-snow. Photograph any damage before repairs, and be alert to falling ice and snow from roofs during the thaw — that injures people for days after the storm ends.

Sources

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