Air Quality in California
California has the most ozone-polluted cities in the nation despite decades of progress.
Monitored days with good air quality
1990–2025U.S. EPA AirData, Annual AQI by County, all monitored California counties.
Monitored days unhealthy for sensitive groups or worse
1990–2025U.S. EPA AirData, Annual AQI by County (AQI above 100).
- •Despite ranking worst for ozone, LA's smog has fallen sharply since the 1970s.
Wildfires in California
Wildfires have become larger and more destructive across California.
Acres burned in tracked wildfires
2013–2026CAL FIRE incident archive (incidents.fire.ca.gov), calendar year; includes the current year to date.
Tracked wildfire incidents
2013–2026CAL FIRE incident archive (incidents.fire.ca.gov), calendar year; includes the current year to date.
- •2020 burned a record 4.3 million acres across California.
Drought in California
California swings between severe drought and intense wet years.
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 in California
Agriculture dominates California's water use.
Sacramento River annual mean flow
1964–2025USGS National Water Information System, annual mean discharge by water year, Sacramento R above Bend Bridge near Red Bluff (11377100).
San Joaquin River annual mean flow
1950–2025USGS National Water Information System, annual mean discharge by water year, San Joaquin R near Vernalis (11303500).
Emissions in California
California has low per-capita emissions despite its large economy.
Energy-related CO₂ emissions
1970–2021U.S. EIA State Energy Data System, all sectors and fuels (FRED EMISSCO2TOTVTTTOCAA).
Transportation CO₂ emissions
1970–2021U.S. EIA State Energy Data System, transportation sector (FRED EMISSCO2TOTVTCTOCAA).
| Indicator | California | U.S. |
|---|---|---|
| Per-capita CO₂e2021 | 9.3 t | 17.6 t |
- •California's per-capita emissions are among the lowest in the U.S.
Climate Indicators in California
California's climate is warming faster than the global average in many regions.
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.