By MATTHEW FUHRMAN and IVAN PEREIRA, ABC News

(LOS ANGELES) — Temperatures in one part of Los Angeles County surged to 121 degrees Sunday, the highest reading ever recorded in that county, as the West Coast grapples with a dangerous heat wave.

The National Weather Service said the San Fernando Valley neighborhood of Woodland Hills recorded a temperature of 121 degrees, two degrees higher than the previous record set in 2006.

California, Nevada and Arizona are in the midst of an excessive heat watch during Labor Day weekend, and the weather is causing air quality issues and strains on power lines.

“The temperature at Woodland Hills may yet go up additionally, and many other records around the region will be broken today,” the NWS said in its report.

In August, California’s heat and thunderstorms led to widespread wildfires that affected several parts of the state.

Several wildfires have erupted this weekend and trapped some residents who live near the woodland areas.

Environmentalists have warned that climate change will make these heat waves longer and more severe.

Elsewhere in California, Gov. Gavin Newsom on Sunday issued an emergency proclamation for the counties of Fresno, Madera and Mariposa due to the Creek Fire; for San Bernardino County due to the El Dorado Fire; and for San Diego County due to the Valley Fire.

Copyright © 2020, ABC Audio. All rights reserved.