Air Quality
Air quality in Idaho is generally good, though summer wildfire smoke and winter inversions in the Treasure Valley cause spikes.
Monitored days with good air quality
1990–2025U.S. EPA AirData, Annual AQI by County, all monitored Idaho counties.
Monitored days unhealthy for sensitive groups or worse
1990–2025U.S. EPA AirData, Annual AQI by County (AQI above 100).
- •Wildfire smoke is now Idaho’s largest source of unhealthy air days.
Wildfires
Idaho experiences significant wildfire activity, with an average of around 400,000 acres burned annually.
Drought
Roughly 40% of Idaho has experienced drought conditions in recent years, straining agricultural 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.
Water Usage
Irrigation dominates Idaho water use, drawing heavily on the Snake River and its underlying aquifer.
Emissions
Idaho's per-capita CO2 emissions of about 9.8 metric tons are among the lowest of any U.S. state, thanks to its clean hydropower grid.
Energy-related CO₂ emissions
1970–2021U.S. EIA State Energy Data System, all sectors and fuels (FRED EMISSCO2TOTVTTTOIDA).
Transportation CO₂ emissions
1970–2021U.S. EIA State Energy Data System, transportation sector (FRED EMISSCO2TOTVTCTOIDA).
| Indicator | Idaho | U.S. |
|---|---|---|
| CO2 emissions per capita (metric tons) | 9.8 | 14 |
Climate Indicators
Idaho has warmed roughly 2°F since 1900, with earlier snowmelt in the Rockies shrinking summer river flows.
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.
- •Idaho’s mountain snowpack is the state’s largest water reservoir.