During the 2019-2020 winter season (November through February), the Valley continued to demonstrate significantly improved air quality. Despite experiencing one of the driest winter seasons on record, the Valley continues to progress towards attaining the federal PM2.5 standards. These continued improvements in air quality would not have been possible without the emissions reductions achieved under the District’s control strategies, including the comprehensive residential wood burning emissions reduction strategy, as well as the commitment from the Valley’s residents to reduce emissions in their daily activities. In fact, the Valley still meets the 65 µg/m3 federal 24-hour PM2.5 standard and is continuing to make progress towards the 35 µg/m3 standard.
The San Joaquin Valley experienced record improvements across several key 8-hour ozone metrics in 2019, including the fewest number of days exceeding the 84 ppb, 75 ppb, and 70 ppb federal standards, and the Valley’s lowest federal “design value” (official metric used to determine whether an area is in attainment of federal standards). The Valley’s progress in lowering ozone pollution concentrations has been achieved despite being influenced from many challenging factors, including long strings of high summertime temperatures, extreme wildfires in recent years, and extended periods of atmospheric stability where pollution easily builds in the bowl of the Valley.
These improvements would not be possible without the success of the District’s control strategy through its various attainment planning efforts, robust incentive programs, strong public education efforts, commitment and significant investment from Valley businesses and residents, the agricultural community, and other stakeholders in doing their part to reduce emissions.