Sacramento-Roseville-Arden-Arcade, CA
- High ozone days per year: 94
- No. of days with unhealthy particle pollution: 6
- People with asthma: 175,185
- Population: 2,324,884
Rising temperatures and heat waves are partially to blame for the Sacramento area’s high ozone levels — as do automobile and freight vehicle emissions. Smoke from California’s frequent forest fires also contributes to days of extremely high particle pollution.