Code Red: Unhealthy Air Quality From Wildfire Smoke Blankets MD

MARYLAND — A "code red" air quality alert has been issued for all of Maryland on Thursday as smoke from Canadian wildfires covers the region, the Maryland Department of the Environment said, making the air quality unhealthy for everyone.

Thursday's air quality index of 167 in Baltimore is higher than the 127 that was registered on Wednesday. At those levels, the air quality is considered unhealthy for sensitive groups. An API of 50 or below is considered safe.

On Wednesday, winds from the northwest pushed more Canadian wildfire smoke from the Great Lakes to the Mid-Atlantic states. While this concentrated unhealthy air quality over western Maryland, the conditions have spread steadily statewide.

A high pressure system moving into the region on Thursday morning will combine with calming winds and surface inversions to trap and concentrate the smoke close to the surface, according to MDE.

"As a result, concentrations of PM2.5 due to smoke on Thursday morning will be notably elevated, with hourly concentrations pushing towards equivalent 'code purple' in some locations, mainly along and north of I-95 toward the Pennsylvania line," MDE said. "Some moderation of concentrations will occur during the day Thursday, but daily average concentrations for most locations are expected in the Unhealthy, red AQI range."

Under a code red alert, anyone can experience health effects, but they will be more serious for people in sensitive groups, the Metropolitan Washington Council of Governments said. Everyone is advised to stay inside, including older adults, children, teens and people with heart or lung disease, according to AirNow.gov says.

Wearing a mask may help limit irritation for those suffering from respiratory illnesses, according to officials.

About 127 million people across the country, from the Midwest to the Mid-Atlantic, are under air quality alerts Thursday, according to NBC News.

Temperatures near 90 degrees will foster Unhealthy for Sensitive Groups ozone, enhancing USG ozone in the southern portions of the state, particularly northeast of D.C. and in Baltimore.

Breezes from the Chesapeake Bay later in the day may spread high concentrations of unhealthy ozone and smoke across the northern coastal areas of the bay. These winds may push the harmful ozones and smoke in a southerly direction on Friday. This may lessen the concentrations of bad air in the region, though smoke is expected to linger statewide.

Air quality is expected to improve with an AQI of 102 (orange) forecast for Friday. Air quality will still be unhealthy for sensitive groups. On Saturday, an AQI of 80 (yellow) is predicted, which is moderately unhealthy.

Across Canada, 490 fires are burning, with 255 fires considered to be out of control. The small particles in wildfire smoke can irritate the eyes, nose and throat, and can affect the heart and lungs, making it harder to breathe.

The Canadian Interagency Forest Fire Centre reported Monday that more than 29,000 square miles of land, including forests, has burned across Canada since Jan. 1. Nearly a quarter of the fires burning in Canada are in Quebec, where recent rainfall has helped in firefighting efforts but has not been enough to extinguish the fires.

Skies over the Baltimore-Washington area will be hazy on Thursday, with a high of 87, according to the National Weather Service. It become mostly clear in the evening, with a low of 65. Friday is expected to be mostly sunny, with a chance of showers later in the day

Here is the five-day Maryland forecast from the National Weather Service:

Thursday: Widespread haze. Areas of smoke. Sunny, with a high near 87. Calm wind becoming south around 6 mph in the afternoon.

Thursday Night: Mostly clear, with a low around 70. Southeast wind around 6 mph.

Friday: A chance of showers and thunderstorms, mainly after 5pm. Mostly sunny, with a high near 89. South wind 6 to 10 mph. Chance of precipitation is 30%.

Friday Night: A chance of showers and thunderstorms before 8pm, then showers likely and possibly a thunderstorm between 8pm and 2am, then a chance of showers after 2am. Mostly cloudy, with a low around 72. South wind around 9 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Saturday: A chance of showers, with thunderstorms also possible after 11am. Mostly cloudy, with a high near 88. South wind around 7 mph. Chance of precipitation is 50%.

Saturday Night: Showers likely and possibly a thunderstorm before 2am, then a chance of showers. Mostly cloudy, with a low around 74. Chance of precipitation is 60%.

Sunday: A chance of showers before 8am, then a chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 88. Chance of precipitation is 50%.

Sunday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 74. Chance of precipitation is 50%.

Monday: A chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 90. Chance of precipitation is 50%.

Monday Night: A chance of showers and thunderstorms before 2am. Mostly cloudy, with a low around 74. Chance of precipitation is 40%.

Tuesday: A chance of showers and thunderstorms. Mostly sunny, with a high near 90. Chance of precipitation is 30%.

Tuesday Night: A chance of showers and thunderstorms. Partly cloudy, with a low around 74. Chance of precipitation is 30%.

Wednesday: A chance of showers and thunderstorms. Mostly sunny, with a high near 91. Chance of precipitation is 30%.