SkyGround

County-level natural hazard risk data for researchers

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Arapahoe County, CO

Population: 654,201 · FIPS code: 08005

Relatively Moderate Overall risk index: 93.8 / 100 (percentile among US counties)

Hazard breakdown

Hazard NRI rating NRI score NOAA events
(2016–2025)
Wildfire Relatively Low 84.7 0
Inland Flooding Relatively Moderate 92.5 7
Coastal Flooding Not Applicable — 0
Earthquake Relatively Low 85.5 —
Heat Wave Relatively Low 68.6 0
Tornado Relatively High 97.2 11

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

Arapahoe County has been included in 12 federal disaster declarations between 1965 and 2023, most recently for Flood in 2023 (SEVERE STORMS, FLOODING, AND TORNADOES).

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

Arapahoe County sits at approximately 47.4°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 Arapahoe 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.