David Contreras places a cold towel on his neck to cool off while talking to ARCHES outreach workers as temperatures exceed 100 degrees in Salem, Oregon on Thursday, Aug. 12, 2021. Salem Heatwave 123
Los Angeles, California – Southern California is entering a stretch of dangerously hot weather, with temperatures expected to surge well above seasonal norms starting Monday and continuing through the workweek, according to the National Weather Service (NWS).
The heat wave will primarily impact inland areas, with coastal regions seeing only moderate increases in temperature. Areas such as the San Fernando Valley are forecast to experience the brunt of the heat, with highs expected to top 100 degrees from Tuesday through Thursday. Woodland Hills, for example, could see highs of 103 degrees on Wednesday and 101 on Thursday. Monday and Friday will also be hot, with predicted highs of 94 and 96 degrees, respectively.
This extended period of high pressure over the region is not only expected to bring oppressive heat but also contribute to deteriorating air quality. Beginning Monday, many inland locations are likely to fall into the “Moderate” or “Unhealthy for Sensitive Groups” air quality categories due to pollutants being trapped near the surface. The sinking air associated with high-pressure systems hampers dispersion of pollutants, making it harder for air to clear.
Forecasters also warn of elevated fire weather conditions, particularly in the mountains, deserts, and interior valleys. The combination of hot, dry weather and gusty winds could significantly increase the risk of grass fires throughout the week.
While temperatures will climb steadily starting Sunday, the hottest days are expected to be midweek. Tuesday will mark a sharp jump in temperature across much of the region. Downtown Los Angeles could see highs in the low 90s, while many valley locations will reach or exceed 100 degrees. The conditions resemble those typically seen in late summer or early fall, not mid-May.
This week’s heat wave follows a cooler weekend that brought patchy drizzle and highs in the 60s across much of Southern California. However, a strong high-pressure ridge building over the area will erase the marine influence, sending temperatures soaring.
Relief is in sight by the end of the week, with a return of onshore flow expected to usher in a gradual cooling trend beginning Thursday and continuing into the weekend. Until then, residents are advised to take precautions, especially in the afternoon hours when temperatures will peak.
