Tornado Risk in Boone County, IL
Boone County's tornado history, by the numbers
23 tornado tracks have crossed Boone County since 1958 by NOAA's count, roughly one every 3.3 years - the Moderate band on this site's scale. That is the 57th percentile nationally for tornado frequency. Within Illinois alone, Boone County ranks 65 of 102 counties for tornado frequency.
The number that matters more than frequency
Yes. Boone County has recorded 2 EF4 or EF5 tornados - the strength FEMA's own safe-room guidance is built around, because a standard code-built house is not expected to survive those winds without a hardened room. A county can be lower-frequency overall and still carry this history.
Shelter and safe-room economics
Illinois does not currently have a confirmed state rebate layered on top of FEMA's 75% Hazard Mitigation cost-share, so a Boone County homeowner should expect the full national range: $2,890-$13,280, $7,645 typical.
Power after the storm, not just shelter during it
A direct hit is not required for Boone County to lose power - outbreak-wide outages across Illinois regularly reach homes and businesses well outside the actual tracks. A battery bank covers that gap without a generator's fuel and venting needs.
What Boone County's figure does not tell you
Boone County's figure is county-wide, not address-specific. Boone County covers about 281 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. Boone County has about 53,313 residents.