Tornado Risk in Clarke County, IA
Clarke County, IA: what NOAA's tornado record says
19 tornado tracks have crossed Clarke County since 1964 by NOAA's count, roughly one every 4 years - the Moderate band on this site's scale. That is the 48th percentile nationally for tornado frequency. Within Iowa alone, Clarke County ranks 90 of 99 counties for tornado frequency.
The number that matters more than frequency
No violent (EF4-5) tornado has been recorded in Clarke County in NOAA's 76-year database. Of its 19 recorded tracks, 12 were weak (EF0-1) and 7 significant (EF2-3).
Shelter and safe-room economics
Iowa does not currently have a confirmed state rebate layered on top of FEMA's 75% Hazard Mitigation cost-share, so a Clarke County homeowner should expect the full national range: $2,890-$13,280, $7,645 typical.
Power after the storm, not just shelter during it
Power loss after a tornado outbreak in Iowa often reaches homes the storm itself never touched. A battery-backup unit covers the outage without the fuel and venting a generator needs.
What Clarke County's figure does not tell you
Clarke County's figure is county-wide, not address-specific. Clarke County covers about 431 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. Clarke County has about 9,524 residents.