PlainQuake

U.S. state profile · USGS ComCat

Earthquakes in Colorado

Colorado has catalogued 12 M4+ earthquakes since 2005 (ranked 20th of 39 U.S. states), with the strongest reaching magnitude M5.3.

Colorado ranks 20th of 39 U.S. states and territories by catalogued seismic activity - a state with limited seismic activity, averaging about 1 M4+ events a year alongside 0 significant M6+ earthquakes since 1900. Below: the full M6+ event history, magnitude and depth profile, and yearly trend.

12
M4+ events (since 2005)
0
Major M6+ (since 1900)
M5.3
Strongest
~1
M4+ per year

The verdict

Colorado is below the global median in catalogued seismic activity, with 12 M4+ earthquakes logged since 2005 and 0 major M6+ events since 1900, the strongest reaching magnitude 5.3.

N/A
no yearly breakdown available
N/A
average recorded event depth
0%
of events are shallow (<70 km, the most damaging kind)

Average catalogued magnitude is 4.3 - most events are moderate tremors felt but rarely damaging.

Colorado's M4+ count vs. every tracked state

Total catalogued M4+ events since 2005, USGS ComCat

12 Top 54% higher than 46% of 39 states

0–100: 30 states (77%). This entry sits in this band. 100–200: 1 states (3%). Above this entry. 200–300: 4 states (10%). Above this entry. 300–400: 0 states (0%). Above this entry. 400–500: 0 states (0%). Above this entry. 500–600: 0 states (0%). Above this entry. 600–700: 0 states (0%). Above this entry. 700–800: 0 states (0%). Above this entry. 800–900: 1 states (3%). Above this entry. 900–1,000: 0 states (0%). Above this entry. 1,000–1,100: 3 states (8%). Above this entry. Colorado 0 1,000+ every tracked state, bucketed by value

Each bar is a 100-wide band; taller bars hold more states. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Source USGS Comprehensive Earthquake Catalog (ComCat) · 2005-present

How Colorado compares to its nearest peers

Colorado ranks in the 46th percentile for M4+ frequency among all 39 tracked U.S. states and territories. Plotted here against its 20 nearest-ranked peers by how OFTEN they shake (M4+ count) against how HARD the strongest one ever hit (max recorded magnitude).

Colorado vs. its 20 nearest-ranked peer states, USGS ComCat

Colorado vs. its 20 nearest-ranked peer states, USGS ComCat 2×2 strategic matrix plotting 21 entities by M4+ events since 2005 (X) and Strongest recorded magnitude (Y), with a crosshair dividing the plot into four quadrants. Frequent and severeRare but severeFrequent, capped so farLower on both axes -50050100150 M3M4M5M6M7 M4+ events since 2005 Strongest recorded magnitude
Colorado vs. its 20 nearest-ranked peer states, USGS ComCat
Read the chart (all 21 values)
State M4+ events Strongest magnitude
Oklahoma 97 M5.8
Idaho 73 M6.5
Georgia 67 M6.0
Texas 52 M5.4
New Mexico 37 M5.4
Montana 28 M5.8
Utah 25 M5.7
American Samoa 24 M5.8
Washington 17 M4.7
Wyoming 13 M4.8
Colorado (this page) 12 M5.3
Kansas 12 M4.9
Arizona 7 M5.3
Arkansas 5 M4.7
Louisiana 5 M5.3
Virginia 5 M5.8
Illinois 3 M5.2
Tennessee 3 M4.4
Missouri 2 M4.0
Nebraska 2 M4.1
Delaware 1 M4.1

USGS seismic hazard context

PGA hazard tiers from the USGS National Seismic Hazard Map, the design-basis shaking used in building codes. These are the national distribution of hazard tiers across all US land area, not a Colorado-specific breakdown; Colorado's own position within these tiers depends on its local geology and fault proximity.

HazardHazard, Low (PGA <0.05g): 35%35%Hazard, Moderate (0.05-0.15g): 32%32%Hazard, High (0.15-0.30g): 22%22%Hazard, Very High (>0.30g): 11%11%Low (PGA <0.05g)Moderate (0.05-0.15g)High (0.15-0.30g)Very High (>0.30g)
PGA hazard tiers (50-year design life) - National distribution, USGS National Seismic Hazard Map 2023 (USGS NSHM)

Frequently asked questions

How many earthquakes hit Colorado?
The USGS catalog records 12 magnitude-4-and-above earthquakes in Colorado since 2005, about 1 per year, plus 0 major (M6+) events catalogued back to 1900.
What was the largest earthquake in Colorado?
The strongest catalogued earthquake in Colorado measured magnitude 5.3. The average magnitude across the M4+ catalog is 4.3.
How does Colorado rank for earthquakes?
Among U.S. states and territories, Colorado ranks 20th of 39 by catalogued M4+ activity - a state with limited seismic activity.
Where does this data come from?
All figures come from the USGS Comprehensive Earthquake Catalog (ComCat). M4+ counts cover 2005 onward; the significant-event series covers M6+ back to 1900.

About this data

Every figure on this page is computed directly from the USGS Comprehensive Earthquake Catalog (ComCat), the public-domain record maintained by the USGS Earthquake Hazards Program. State assignment uses USGS place-name geocoding. Two series are combined: a worldwide catalog of magnitude-4.0-and-above events from 2005 onward - the period over which the global seismograph network reliably detects and locates earthquakes everywhere, and a historical series of significant magnitude-6.0-and-above events stretching back to 1900. Magnitudes use the moment-magnitude scale (Mw), the modern standard that supersedes the older Richter scale; because the scale is logarithmic, each whole step represents roughly thirty-two times more energy released. Depth is measured in kilometres from the surface, and shallow earthquakes generally produce stronger surface shaking than deep ones of the same magnitude. Counts reflect what instruments recorded, not every tremor that occurred, and recent events can be revised as seismologists refine the catalog.

Source: USGS ComCat, verify with USGS → · See our methodology for the full pipeline.

Disclaimer: PlainQuake is an informational reference for informational purposes only, not an emergency or early-warning service, and not professional engineering or safety advice. For official alerts and guidance, consult the USGS and your local emergency authorities. See our full disclaimer.

What Colorado's numbers mean

Colorado ranks 20th of 39 U.S. states and territories - a state with limited seismic activity.

  • See Colorado's computed risk level alongside every other state, using the same USGS-derived methodology. Open the risk calculator
  • 0% of Colorado's catalogued major earthquakes are shallow (under 70km) - shallow events generally produce stronger surface shaking than deep ones of the same magnitude. How depth affects shaking
  • Compare Colorado against every other U.S. state by count and maximum magnitude. See the full state ranking

Figures reflect the USGS ComCat catalog (M4+ since 2005, M6+ significant events since 1900) - not a real-time hazard assessment. For official guidance, see the USGS Earthquake Hazards Program.

According to the US Geological Survey Earthquake Hazards Program, PlainQuake's figures are rendered directly from 315,341 recorded M4+ earthquakes and 14,428 significant M6+ events (USGS ComCat, 2005-present) -- no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-07-19.