SkyGround

County-level natural hazard risk data for researchers

All counties

Jefferson County, CO

Population: 582,825 · FIPS code: 08059

Relatively High Overall risk index: 94.9 / 100 (percentile among US counties)

Hazard breakdown

Hazard NRI rating NRI score NOAA events
(2016–2025)
Wildfire Relatively High 99.5 0
Inland Flooding Relatively High 93.4 4
Coastal Flooding Not Applicable — 0
Earthquake Relatively Low 84 —
Heat Wave Relatively Low 71 0
Tornado Relatively High 96.5 0

NOAA event counts are recorded county-level storm events from the NOAA Storm Events Database for 2016–2025. NOAA does not track earthquakes, and some hazard reports are filed by NWS forecast zone rather than county, so these counts are a partial, not exhaustive, record of recent activity. See the methodology page for details.

Federal disaster declaration history

Jefferson County has been included in 15 federal disaster declarations between 1969 and 2024, most recently for Fire in 2024 (QUARRY FIRE).

Source: FEMA OpenFEMA Disaster Declarations Summaries. Counts reflect county-level declaration records (a single disaster can produce more than one record per county), not modeled risk.

Geomagnetic latitude

Jefferson County sits at approximately 47.2°N geomagnetic latitude. Aurora is rarely visible this far from the geomagnetic poles, even during the most severe (G5) geomagnetic storms — though historic extreme storms have occasionally been seen at unusually low latitudes. See current space weather conditions for live geomagnetic activity and aurora forecasts.

Geomagnetic latitude is an approximate dipole-model calculation based on this county's geographic centroid (US Census Bureau). See the methodology page for details and limitations.

What these ratings mean

Each score reflects how Jefferson County's expected losses from that hazard compare to every other county in the country, based on FEMA's National Risk Index. A "Very High" rating means this county is among the most exposed in the US for that hazard relative to other counties — it does not mean a disaster is likely this year. See the methodology page for how these scores are calculated.