How Likely Is a Tornado in Roberts County, SD?
Roberts County, SD: what NOAA's tornado record says
Roberts County has recorded 31 tornado touches in NOAA's 76-year database, a rate of roughly one every 2.5 years - our Elevated band. Put another way: Roberts County sees more tornado activity than 70% of US counties. Within South Dakota alone, Roberts County ranks 26 of 66 counties for tornado frequency.
Beyond the frequency band: violent history
27 weak and 4 significant tornadoes make up Roberts County's 31-track record - none violent. NOAA has never logged an EF4 or EF5 crossing this county.
The dollar figure Roberts 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
A direct hit is not required for Roberts County to lose power - outbreak-wide outages across South Dakota 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 this number is, and is not
One caveat before relying on Roberts County's number: it is county-wide, and it covers about 1,101 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. Roberts County has about 10,283 residents.