San Juan County, WA: Tornado Risk and Shelter Cost
San Juan County, WA: what NOAA's tornado record says
NOAA's Storm Prediction Center has no recorded tornado touching San Juan County in the 76 years of the database, 1950 through 2025. That is a real result, not a gap in the data - most of the Northeast and Pacific coast reads this way. Against the rest of the country, that is the 2nd percentile for frequency. Within Washington alone, San Juan County ranks 36 of 39 counties for tornado frequency.
Has San Juan County ever had a violent tornado?
Nothing violent in San Juan County's file: 0 tracks total, topping out at significant (EF2-3) strength on 0 of them, zero at EF4-5.
Paying for it, if San Juan County's history says you should
A storm shelter or in-residence safe room typically runs $2,890-$13,280 nationally, around $7,645 for a common single-family installation. No state-administered rebate program specific to Washington was confirmed for this site - FEMA's own Hazard Mitigation Assistance grants fund 75% of an approved safe room nationwide, but only some states currently run a homeowner-facing application on top of that.
The gap a shelter does not cover
A direct hit is not required for San Juan County to lose power - outbreak-wide outages across Washington regularly reach homes and businesses well outside the actual tracks. A battery bank covers that gap without a generator's fuel and venting needs.
County-level, not address-level
Treat this as a county-wide figure, not a prediction for one address. San Juan County covers about 174 square miles, so a single touch here counts the same as a single touch in a county a fraction of that size. And records from before the 1990s, NOAA notes, undercount weaker tornadoes in areas with less storm-spotting coverage at the time. San Juan County has about 18,668 residents.