Tornado Risk in Jefferson County, TN
Jefferson County, TN: what NOAA's tornado record says
10 tornado tracks have crossed Jefferson County since 1955 by NOAA's count, roughly one every 7.6 years - the Low band on this site's scale. That is the 29th percentile nationally for tornado frequency. Tennessee has 95 counties in this dataset; Jefferson County ranks 66 of them by frequency.
The number that matters more than frequency
No violent (EF4-5) tornado has been recorded in Jefferson County in NOAA's 76-year database. Of its 10 recorded tracks, 9 were weak (EF0-1) and 1 significant (EF2-3).
Shelter and safe-room economics
Tennessee does not currently have a confirmed state rebate layered on top of FEMA's 75% Hazard Mitigation cost-share, so a Jefferson 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 Jefferson County to lose power - outbreak-wide outages across Tennessee 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 Jefferson County's figure does not tell you
Jefferson County's figure is county-wide, not address-specific. Jefferson County covers about 275 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. Jefferson County has about 59,217 residents.