Story County, IA Tornado Risk & Storm Shelter Cost
Story County's tornado history, by the numbers
Since 1950, NOAA has logged 66 tornado tracks crossing Story County - one about every 1.2 years, which lands it in our High band. Nationally, Story County ranks at the 94th percentile for tornado frequency. Among 99 Iowa counties in this dataset, Story County ranks 3 for how often a tornado touches down.
Story County's EF4-5 history
Story County has 2 violent (EF4-5) tornados on record. FEMA centers its safe-room case on exactly this strength, not on how often a county gets touched - a hardened room is the difference between a code-built house surviving an EF4-5 or not.
What a storm shelter costs near Story County
For a Story County homeowner, budget $2,890-$13,280 for a shelter or safe room ($7,645 typical) - this pass found no Iowa-specific rebate on top of FEMA's underlying 75% national cost-share program.
The outage nobody plans for
The storm that misses Story County outright can still take its power out - outbreak-scale outages across Iowa are common well beyond the tracked path. A battery-backup unit handles that without a generator's setup or fuel.
Read this before you rely on it
This is a county-level figure, not a per-address probability. Story County covers about 573 square miles, so a single touch here counts the same as a single touch in a county a fraction of that size. Pre-radar-era records (before the 1990s) are also documented by NOAA as undercounting weaker tornadoes in sparsely-instrumented areas. Story County has about 102,498 residents.