How Likely Is a Tornado in McPherson County, SD?
McPherson County, SD: what NOAA's tornado record says
McPherson County has recorded 26 tornado touches in NOAA's 76-year database, a rate of roughly one every 2.9 years - our Elevated band. Put another way: McPherson County sees more tornado activity than 61% of US counties. South Dakota has 66 counties in this dataset; McPherson County ranks 37 of them by frequency.
Beyond the frequency band: violent history
19 weak and 6 significant tornadoes make up McPherson County's 26-track record - none violent. NOAA has never logged an EF4 or EF5 crossing this county.
The dollar figure McPherson 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
Power loss after a tornado outbreak in South Dakota often reaches homes the storm itself never touched. A battery-backup unit covers the outage without the fuel and venting a generator needs.
What this number is, and is not
One caveat before relying on McPherson County's number: it is county-wide, and it covers about 1,137 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. McPherson County has about 2,307 residents.