Southern California’s Wet Winter Brought Cleaner Air and Fewer No-Burn Days

Due to this winter’s potentially drought-busting rainy weather, the region has only had eight no-burn days, the fewest since the 2012-2013 winter season when only five no-burn alerts were issued. 

“In spite of this winter’s relatively low number of no-burn days, we are continuing to seek the public’s help to stay informed of, and comply with, no-burn alerts through our Check Before You Burn program,” said Wayne Nastri, SCAQMD’s executive officer.

This list shows the significant differences over the past five Check Before You Burn seasons: 

• 2012-2013 – 5 days1 
• 2013-2014 – 16 days
• 2014-2015 – 25 days
• 2015-2016 – 14 days
• 2016-2017 – 8 days

Wet winters typically result in cleaner air quality for PM2.5 (fine particulate matter) because the rain cleanses the air and storms create unsettled conditions in the atmosphere preventing the buildup of pollutants.  

Under the Check Before You Burn program, the SCAQMD, in consultation with staff meteorologists, will issue a 24-hour no-burn alert for residential fireplaces and outdoor fire pits and wood stoves when stagnant weather raises PM2.5 to the upper Moderate range or higher. 

Alerts are issued when elevated levels of PM2.5 are forecast for specific areas or the entire South Coast Air Basin. The Check Before You Burn season runs every year from November 1 through the last day of February. 

Favorable weather this winter, including stronger winds and significant rainfall, led to better dispersion and more pollutants being washed out of the air instead of building up over several days.

Ongoing emission controls such as no-burn day restrictions, home owners that replaced their wood-burning fireplaces and stoves with natural gas logs encouraged by SCAQMD incentives, and fireplace limitations for new homes, as well as other significant programs like the diesel truck incentive programs also helped improve air quality this winter.

PM2.5 are particles less than or equal to 2.5 micrometers in diameter -- a fraction of the width of a human hair -- are so small that they can get deep into the lungs, cause throat and eye irritation, aggravate asthma and trigger other respiratory conditions.  Breathing high levels of PM2.5 over long periods of time can also cause more serious health problems.
Although some might consider wood smoke “natural,” smoke caused by burning wood in fireplaces can emit more than five tons of harmful PM2.5 emissions per day in the South Coast Air Basin – more than three times the amount of PM2.5 emitted from all of the power plants in the Southland. 

SCAQMD is the air pollution control agency for Orange County and major portions of Los Angeles, San Bernardino and Riverside counties.


1For the 2013-2014 wood-burning season, the threshold for forecasting a no-burn day was lowered from 35 micrograms per cubic meter (ug/m3) of PM2.5 to 30 ug/m3).  Therefore, if today’s threshold had been in effect in 2012-2013, there would likely have been more no-burn days forecast.