Adams County, Colorado

What hazards hit Adams County most?

The most frequent records are hail reports: 502 since 1955. 65% of its hail reports since 1955 fell in May and June. The rank column places the county among Colorado's counties by days with a record per 1,000 square miles of land over each hazard's complete period.

Source: NOAA NCEI Storm Events Database (county and forecast-zone records attributed to the county; a zone record shows its own totals on each county it covers). Days: dates with at least one record of the hazard in the county. Ranks: days with a record per 1,000 square miles of land (Census Bureau 2024 Gazetteer), since 1950 for tornadoes, 1955 for hail and thunderstorm wind, 1996 for the rest.

How many tornadoes has Adams County had?

NOAA records 192 tornadoes in Adams County from 1953 to 2025, the strongest rated F3, with 0 deaths and 43 injuries recorded in the county. That is 2nd of 63 Colorado counties and 21st of 3,080 U.S. counties by days with tornadoes per 1,000 square miles since 1950. A tornado that crossed a county line is counted in each county it touched, with the length of its path inside the county.

Counted as whole tornadoes rather than county records, the Storm Prediction Center's database holds 194 tornadoes whose track touched Adams County since 1950 (NOAA's county records number 192: they file a crossing tornado once per county segment, and the two databases differ on some tracks); along their whole tracks they killed 0 people.

Map of the strongest tornado tracks in Colorado.

Source: NOAA NCEI Storm Events Database, tornado records by county (path length in the county, maximum width); ratings as published: F scale before February 1, 2007, EF scale after. Whole-track figures: NOAA Storm Prediction Center tornado database (1950-2025). SPC severe weather database.

When was the last damaging storm in Adams County?

The most recent record with damage, injuries or deaths is the July 8, 2025 thunderstorm wind ($1,000 in damage in 2025 dollars).

Source: NOAA NCEI Storm Events Database; every record of 2025-2026 is listed, earlier ones when they caused deaths, injuries or $250,000 of damage (2025 dollars), and every tornado.

The deadliest and costliest records

Source: NOAA NCEI Storm Events Database: deaths and injuries direct and indirect; damage is property plus crops as estimated by the National Weather Service, converted to 2025 dollars.

Is it getting more frequent?

Records per decade for Adams County's most frequent hazards. Counts rose everywhere after 1996, when NOAA began recording every event type, so compare decades within a hazard's complete period only (the shaded cells come before it).

Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).

What time of year?

65% of its hail reports since 1955 fell in May and June. The two busiest months are in violet.

Source: NOAA NCEI Storm Events Database, records by the month they began.

Federal disaster declarations for Adams County

FEMA's register lists 12 declarations that include Adams County: 7 major disasters, 5 emergencies and 0 fire management assistance declarations. Most were for flood (5) and biological (2).

Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), declarations through October 2, 2026; one declaration is counted once however many areas it names. OpenFEMA dataset page.

How many floods has Adams County had?

NOAA's Storm Events Database holds 26 flood or flash flood records for Adams County from 1997 to 2025, on 20 days, with 1 death. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Adams County ranks 1073rd of 2,942 U.S. counties.

The National Flood Insurance Program has paid $594,000 on 154 claims filed in Adams County; the most in one year was 17 in 1984. Claims count insured losses only: uninsured flood damage is not in this file.

Source: FEMA OpenFEMA NFIP Redacted Claims, as of September 8, 2026; claims by year of loss, payments in the dollars of the year paid. OpenFEMA dataset page.

FEMA's modeled risk for Adams County

FEMA's National Risk Index rates Adams County Relatively Moderate overall, with an expected annual loss of $131 million. These are FEMA's model estimates of future loss from 18 hazards, not a count of what happened; they can differ from the record above.

Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.

Counties that share a border with Adams County

1. Weld County 2,459
2. Jefferson County 1,455
3. Arapahoe County 1,390
4. Washington County 1,319
5. Adams County 1,310
6. Morgan County 993
7. Denver County 852
8. Broomfield County 119

Source: U.S. Census Bureau county adjacency file; NOAA NCEI Storm Events Database, records since 1950. The Census Bureau's adjacency file.

Next

• Tornadoes in ColoradoEvery Colorado tornado since 1950 and the counties with the most per square mile
• Hail in ColoradoThe state's hail reports, by county, year and month
• The Colorado recordEvery hazard in the state, its deadliest events and its federal declarations
• FEMA's risk rating for each hazard in Adams CountyThe hazard risk calculator: 18 hazards beside the county's record
• Download Adams County's FEMA declarations (CSV)12 rows: every declaration that named the county, for your own analysis