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