Spare the Air alert extended across Bay Area through weekend

Bay Area air-quality officials extended a Spare the Air alert through the weekend after several days of windless weather allowed pollution and haze to build up across the region. With the stagnant pattern expected to persist for several days, some monitoring sites registered air quality in "unhealthy for sensitive groups" or worse, prompting officials to urge precautions.

The alert, announced Jan. 15, singled out people with respiratory conditions, children and older adults as most at risk. Officials advised residents to limit strenuous outdoor activity and to avoid wood-burning and fireworks, both of which can spike fine particulate matter and worsen smoke and haze. The guidance applies across San Francisco County, where dense urban populations and frequent outdoor activity mean more people can feel the effects of degraded air on daily life.

For San Franciscans, the impacts are immediate and practical. Parents and school staff may need to scale back or relocate recess and outdoor practices. Outdoor workers — from construction crews to delivery cyclists — face higher exposure during long shifts. People experiencing homelessness and those in poorly ventilated housing are particularly vulnerable, as they may have fewer options to escape smoky conditions. Community health clinics and senior centers should anticipate greater demand from residents with breathing difficulties or heart conditions.

Meteorological conditions tied to the alert are straightforward: light winds and a stable atmosphere limit dispersion of pollutants from traffic, residential heating and other sources. Without the usual bay breezes to clear the air, particulates and ozone can accumulate near the ground, raising readings on the Air Quality Index and producing visible haze across streets and waterfronts.

Residents can reduce local pollution and personal exposure by heeding the official advice: postpone vigorous outdoor exercise, refrain from lighting wood fires or using outdoor firepits, and skip fireworks. Where possible, stay indoors during peak pollution periods, keep windows closed if outdoor smoke is heavy, and use portable or built-in filters with HEPA or high-efficiency settings. Employers with outdoor staff should consider adjusting schedules or providing respiratory protection.

Officials will continue monitoring conditions and reassess when winds return or pollutant levels fall. For now, the Spare the Air alert is a reminder that even in winter, a few calm days can quickly degrade air quality in the Bay Area; taking simple steps now can protect the most vulnerable and help clear the skies sooner.