How Likely Is a Tornado in Lake County, SD?
Lake County, SD: what NOAA's tornado record says
Lake County has recorded 28 tornado touches in NOAA's 76-year database, a rate of roughly one every 2.7 years - our Elevated band. Put another way: Lake County sees more tornado activity than 65% of US counties. Within South Dakota alone, Lake County ranks 33 of 66 counties for tornado frequency.
Beyond the frequency band: violent history
1 tornado touching Lake County reached violent (EF4-5) strength since 1950. That single fact carries more weight for the shelter decision than the county's overall frequency band.
The dollar figure Lake County's rating leads to
Cost nationally: $2,890-$13,280, about $7,645 typical. South Dakota has no state rebate program confirmed here; FEMA's underlying 75% cost-share exists nationwide, but applying through a state program is what usually makes it real, and none was found for South Dakota this pass.
What a direct hit isn't required for
11,006 people live in Lake County, and a tornado outbreak's power loss usually reaches far more of South Dakota than the tracks themselves touch. A portable battery unit is the faster, no-fuel way to bridge that outage.
What this number is, and is not
One caveat before relying on Lake County's number: it is county-wide, and it covers about 563 square miles, so a single touch counts the same as one in a county a fraction of that size. Weaker pre-1990s tornadoes are also documented as undercounted in NOAA's own record. Lake County has about 11,006 residents.