Which counties get the weather that wears this part?

FEMA's National Risk Index puts Grand Forks County, ND, Ward County, ND and Polk County, MN highest for cold waves, about 21.74 events a year, against 1.32 in the median county. Cold waves test the freeze protection and the heater.

Counties with the highest FEMA annualized frequency of cold wave (events per year, 20,000 or more residents)

What it shows: Grand Forks County, ND is the largest at 21.74, followed by Ward County, ND at 21.47; the smallest shown is Beltrami County, MN at 17.09.

Source: FEMA National Risk Index v1.20 (December 2025), county table: annualized frequency per hazard · file downloaded 2025-12

Data and chart by CalcScrape: Coolant Flush