Parts of SCV have ‘very unhealthy’ air quality during heat wave 

Screenshot of South Coast Air Quality Index's ratings of Santa Clarita Valley's air quality.

Public Health issues Excessive Heat Warning, Metrolink announces heat-related delays in AV line 

The South Coast Air Quality Index deemed parts of the Santa Clarita Valley as having “very unhealthy” air amid a summer heat wave that sizzled Southern California.  

Most of the SCV falls under the AQI’s ‘“unhealthy” range but Newhall, Placerita Canyon and a large swath of Canyon Country have breached the threshold into the higher tier — the second highest behind “hazardous.” 

On Saturday, AQI extended a smoke advisory due to three major fires blazing through the Riverside and Moreno Valley areas — the Highland Fire (105 acres), the Reche Fire (437 acres) and the Rabbit Fire (4,413 acres).  

It’s unlikely the fires had an effect locally, however the SCV and the Riverside/Moreno Valley area are the only two areas to have a “very unhealthy” or higher designation in the South Coast region, according to the South Coast AQI’s map. 

The cause of the rise of local AQI scores is smog, according to the National Weather Service — which issued an Air Quality Alert on Friday afternoon. The alert will extend until 11 p.m. on Monday.  

“Elevated levels of ozone (smog) – the predominant summertime pollutant – are likely to result in poor air quality in the afternoon and early-evening hours,” read the NWS’s Air Quality Alert. “Ozone air pollution can cause respiratory health problems, including trouble breathing, asthma attacks, and lung damage. Children, older adults, and people with asthma or COPD may be more sensitive to the health effects of ozone.” 

The alert went on to state that air quality can change depending on the time of day and weather conditions among other factors.  

To help minimize ozone air pollution levels, the NWS suggested the following: 

• Limit the use of gasoline powered lawn and garden equipment until evening hours 

• Conserve electricity and set your air conditioner at a higher temperature 

• Try to delay trips to the gas station and the use of household chemicals until the evening 

To view current and forecasted air quality levels for the SCV area, visit:  

Heat wave 

All of the Southwestern United States experienced a heatwave over the weekend and the SCV was no exception.  

Temperatures reached up to 107 degrees fahrenheit on Saturday and were forecasted to be up to 106 degrees on Sunday accompanied by “minimal relief,” of lower overnight temperatures.  

The scorching temperatures prompted an excessive heat warning for the SCV from both the National Weather Service and the Los Angeles County Department of Public Health.  

SCV’s warning — which is a higher designation than an advisory — was implemented on Friday and will extend until Monday. Public Health urged residents to take precautions to avoid heat-related illness, especially older adults, young children, outdoor workers, athletes, and people with a chronic medical condition who are especially sensitive to negative health impacts from extreme heat.      

“While it is very important that everyone take special care of themselves, it is equally important that we reach out and check on others, in particular those who are especially vulnerable to the harmful effects of high temperatures, including children, the elderly those who are sick or have chronic conditions, pregnant women, those who live alone, and pets,” said Muntu Davis, L.A. County Health Officer. “High temperatures are not just an inconvenience; they can be dangerous and even deadly…. It is critically important to never leave children, elderly people, or pets unattended in homes with no air conditioning and particularly in vehicles, even if the windows are ‘cracked’ or open, as temperatures inside can quickly rise to life-threatening levels. If you have an elderly or unwell neighbor or relative, I encourage you to check on them throughout the day to make sure they are safe and well.” 

Several Cooling Centers have been set up throughout the SCV for residents to seek refuge in, including: 

• Canyon Country Jo Anne Darcy Branch, 18601 Soledad Canyon Road, Santa Clarita, CA 91351.  

• Old Town Newhall Branch, 24500 Main St., Santa Clarita, CA 91321.  

• Valencia Branch, 23743 W. Valencia Blvd. Santa Clarita, CA 91355. 

To view site-specific hours, visit or call 661-259-0750.   

Metrolink announces heat-related delays for Antelope Valley line 

Metrolink announced that all trains may experience a delay due to extreme heat on Saturday.  

On its Twitter page, Metrolink said Each train may experience a 10 to 15 minutes delay because of having to reduce speed. However, the AV line has already experienced delays up to 40 minutes, according to the same Twitter page. 


Related To This Story

Latest NEWS