Tornado Risk in Clay County, SD
Clay County, SD: what NOAA's tornado record says
31 tornado tracks have crossed Clay County since 1965 by NOAA's count, roughly one every 2.5 years - the Elevated band on this site's scale. That is the 70th percentile nationally for tornado frequency. Among 66 South Dakota counties in this dataset, Clay County ranks 25 for how often a tornado touches down.
The number that matters more than frequency
No violent (EF4-5) tornado has been recorded in Clay County in NOAA's 76-year database. Of its 31 recorded tracks, 24 were weak (EF0-1) and 6 significant (EF2-3).
Shelter and safe-room economics
South Dakota does not currently have a confirmed state rebate layered on top of FEMA's 75% Hazard Mitigation cost-share, so a Clay County homeowner should expect the full national range: $2,890-$13,280, $7,645 typical.
Power after the storm, not just shelter during it
The storm that misses Clay County outright can still take its power out - outbreak-scale outages across South Dakota are common well beyond the tracked path. A battery-backup unit handles that without a generator's setup or fuel.
What Clay County's figure does not tell you
Clay County's figure is county-wide, not address-specific. Clay County covers about 412 square miles, so a single touch here counts the same as a single touch in a county a fraction of that size. NOAA also documents that older records undercount weaker tornadoes from before Doppler radar became standard. Clay County has about 15,245 residents.