Tornado Risk in Delaware County, PA
Delaware County's tornado history, by the numbers
6 tornado tracks have crossed Delaware County since 1973 by NOAA's count, roughly one every 12.7 years - the Low band on this site's scale. That is the 20th percentile nationally for tornado frequency. Among 67 Pennsylvania counties in this dataset, Delaware County ranks 59 for how often a tornado touches down.
The number that matters more than frequency
No violent (EF4-5) tornado has been recorded in Delaware County in NOAA's 76-year database. Of its 6 recorded tracks, 4 were weak (EF0-1) and 2 significant (EF2-3).
Shelter and safe-room economics
Pennsylvania does not currently have a confirmed state rebate layered on top of FEMA's 75% Hazard Mitigation cost-share, so a Delaware County homeowner should expect the full national range: $2,890-$13,280, $7,645 typical.
Power after the storm, not just shelter during it
The storm that misses Delaware County outright can still take its power out - outbreak-scale outages across Pennsylvania are common well beyond the tracked path. A battery-backup unit handles that without a generator's setup or fuel.
What Delaware County's figure does not tell you
Delaware County's figure is county-wide, not address-specific. Delaware County covers about 184 square miles, so a single touch here counts the same as a single touch in a county a fraction of that size. NOAA also documents that older records undercount weaker tornadoes from before Doppler radar became standard. Delaware County has about 584,882 residents.