The Sacramento, California metropolitan region is designated by the United States Environmental Protection Agency as a severe non-attainment area for ground-level ozone. About 45 days are designated Unhealthy for Sensitive Groups on the Air Quality Index scale in this region each summer. In 1995, the Sacramento Metropolitan Air Quality Management District started its Spare The Air program, which encourages voluntary driving reduction and notifies the public of possible health effects during high ozone episodes. One important component of the program is the issuance of the Health Advisories (HA), as mandated by California state law when one-hour ozone concentrations are expected to reach 0.15 parts-per-million. During air pollution episodes that reach or are forecast to reach HA criteria, air districts in California are required to alert the news media, public safety officials, health care providers, school officials, and other air agencies within the same air basin with an advisory and protective action recommendations. Air quality nowcasting, much like severe weather nowcasting, plays a crucial role in issuing a HA so that the public is provided warning to reduce exposure to unhealthy air. This paper discusses how real-time air quality observational data and meteorological conditions affect this decision. It also examines the accuracy of forecasts, as well as the ongoing development of both objective and subjective methods for air quality nowcasting in the Sacramento region.