Air Quality
Denver and the Front Range experience periodic ozone alert days in summer due to a combination of vehicle emissions, oil and gas activity, and wildfire smoke.
Monitored days with good air quality
1990–2025U.S. EPA AirData, Annual AQI by County, all monitored Colorado counties.
Monitored days unhealthy for sensitive groups or worse
1990–2025U.S. EPA AirData, Annual AQI by County (AQI above 100).
| Indicator | Colorado | U.S. |
|---|---|---|
| Unhealthy air quality days/yr | 25 | 15 |
Wildfires
Colorado has seen an increase in large wildfires in the 21st century, including the 2020 Cameron Peak and East Troublesome fires, its two largest on record.
| Indicator | Colorado | U.S. |
|---|---|---|
| Acres burned annually (avg, thousands) | 150 | 7000 |
- •The 2020 Cameron Peak Fire was the largest wildfire in Colorado history at over 208,000 acres.
Drought
Colorado experiences recurring drought conditions, particularly in the southwestern part of the state, straining Colorado River water supplies.
Area in drought (D1–D4), yearly average
2000–2025U.S. Drought Monitor (NDMC / USDA / NOAA), average of weekly maps.
Area in extreme or exceptional drought (D3–D4)
2000–2025U.S. Drought Monitor (NDMC / USDA / NOAA), average of weekly maps.
| Indicator | Colorado | U.S. |
|---|---|---|
| Drought share (%) | 25 | 30 |
Water Usage
Water use in Colorado is dominated by agricultural irrigation, with ongoing disputes over Colorado River allocations amid prolonged Western drought.
| Indicator | Colorado | U.S. |
|---|---|---|
| Agricultural water use share (%) | 85 | 80 |
Emissions
Colorado's greenhouse gas emissions are moderate per capita, with oil and gas operations and vehicle traffic along the Front Range the leading sources.
Energy-related CO₂ emissions
1970–2021U.S. EIA State Energy Data System, all sectors and fuels (FRED EMISSCO2TOTVTTTOCOA).
Transportation CO₂ emissions
1970–2021U.S. EIA State Energy Data System, transportation sector (FRED EMISSCO2TOTVTCTOCOA).
| Indicator | Colorado | U.S. |
|---|---|---|
| CO2 per capita (tons) | 12.5 | 14.9 |
Climate Indicators
Colorado's climate ranges from semi-arid plains to alpine mountain zones, with rising average temperatures contributing to earlier snowmelt and longer wildfire seasons.
Average annual temperature
1895–2025NOAA National Centers for Environmental Information, Climate at a Glance, statewide January–December average.
Annual precipitation
1895–2025NOAA National Centers for Environmental Information, Climate at a Glance, statewide January–December total.
| Indicator | Colorado | U.S. |
|---|---|---|
| Temperature rise (°F) | 2.5 | 2.5 |