Heat wave, ongoing wildfires cause unhealthy air quality for parts of Los Angeles County

Smoke and ash from local fires continues to make the air unhealthy for sensitive groups in the Los Angeles area.

The foul air is a result of "the current heat wave, along with stagnant weather and ongoing wildfires,'' said the South Coast Air Quality Management District.

The agency warned that air quality will be unhealthy in several parts of Los Angeles County, mainly for people living near the Ranch Fire burning in Azusa.

It will also be unhealthy for people in eastern San Fernando Valley, including Pomona and Walnut Valley, as well as the Santa Clarita Valley, San Gabriel Mountains and eastern San Gabriel Valley.

The heat wave, which the National Weather Service said is the fourth this summer, is the longest so far, with Tuesday's temperatures expected to match Saturday's high. Some cooling will begin Thursday, but temperatures will not revert to normal before the end of this week, according to ABC7 meterologist Leslie Lopez.

The heat will continue to strain the state's electricity grid. Managers of California's power grid issued a statewide Flex Alert on Sunday, calling for voluntary electricity conservation through Wednesday and warning of rolling blackouts. The Flex Alerts will be in effect from 3-10 p.m. each day.

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The California Independent System Operator urged consumers to help by shifting energy use to morning and nighttime hours and conserving as much energy as possible during the late afternoon and evening hours.

Smoke advisories were issued as a result of the 2,200-acre Ranch Fire, and the 18,500-acre Lake Fire near Castaic.

City News Service contributed to this report.