Delaware issues a Code Red air quality alert for Thursday due to Canadian wildfires

Delaware is under another air quality alert due to lasting effects of the Canadian wildfires.

The Delaware Department of Natural Resources and Environmental Control issued a “Code Orange Air Quality Action Day” on Wednesday morning, followed by a “code red” Thursday morning, due to elevated concentrations of particulate matter 2.5 from Canadian wildfire smoke.

PM 2.5 is defined as fine, inhalable particles or droplets in the air with diameters of 2.5 micrometers and smaller.

The National Weather Service also issued an air quality advisory for the entire state.

What does this mean?

The Wilmington skyline is seen on Friday, June 9, 2023, when Delaware was dealing with hazy skies and poor air quality for a few days due to wildfires in Canada.
The Wilmington skyline is seen on Friday, June 9, 2023, when Delaware was dealing with hazy skies and poor air quality for a few days due to wildfires in Canada.

According to DNREC, light west-northwesterly winds were to bring smoke into Delaware into the early afternoon, while a trough of low pressure was to depart to the east.

This movement caused the Air Quality Index levels to be unhealthy for sensitive groups, defined as “code orange.” The general public is less likely to be affected.

The AQI reveals how clean or polluted air is and what associated health effects might be a concern within a few hours or days of breathing the polluted air. AQI levels are categorized in six levels, ranging from green to maroon as they increase in severity and impact.

Aside from being unhealthy for sensitive groups, the orange zone has an AQI range of 101 to 150. At 5 p.m. Wednesday, the AQI was 134 in New Castle County, 100 in Kent County and 80 in Sussex County.

How long will the air quality impact last?

Haze from Canadian wildfire smoke smothers the Philadelphia skyline on Route 76 near 30th Street Station on Wednesday, June 7, 2023.
Haze from Canadian wildfire smoke smothers the Philadelphia skyline on Route 76 near 30th Street Station on Wednesday, June 7, 2023.

On Thursday, the AQI increased to a code red, defined as “unhealthy” with an AQI ranging from 151 to 200. In this zone, some members of the general public may experience health effects and members of sensitive groups may experience more serious health effects.

At about 8 a.m. on Thursday, The AQI was 155 in New Castle County, 130 in Kent County and 123 in Sussex County.

DNREC previously predicted AQI levels would continue to be in the “unhealthy for sensitive groups” category for PM 2.5, a code orange, on Thursday as winds transport additional smoke into the region.

The smoke will contribute to ozone precursors, too, due to sunny skies and the highs in the mid-80s enhancing ozone formation. As a result, the AQI levels for ozone are expected to increase to high-moderate.

A smoke filled haze from the wildfires in Canada, blankets Belmont Park, on Wednesday, June 7, 2023.
A smoke filled haze from the wildfires in Canada, blankets Belmont Park, on Wednesday, June 7, 2023.

As of Wednesday afternoon, the ozone quality in Delaware was categorized as good with a value of 50. By Thursday morning, the ozone quality was categorized as moderate with a value of 90.

On Friday, DNREC anticipates improved conditions as southeasterly winds begin to lift the smoke to the north.

Lingering smoke will recirculate into the region from the south and warm temperatures will continue to support ozone impacts, causing AQI levels to remain high-moderate.

On Saturday, partly to mostly cloudy skies will limit ozone development as humidity increases across Delaware. Moderate southerly winds will continue to recirculate smoke through the region while also aiding dispersion.

These conditions are expected to lead to mid-moderate AQI levels.

Got a tip or a story idea? Contact Krys'tal Griffin at kgriffin@delawareonline.com 

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This article originally appeared on Delaware News Journal: What is the air quality today? Code Red alert for DE from wildfires