The sun setting into Lake Michigan creating a kaleidscope of colors looks beautiful, but during wildfire seasons, it more than likely indicates harmful concentrations of smoke particles in the atmosphere. (Photo by Kevin Dooley is licensed under CC BY 2.0.)

ST. PAUL — If you’ve noticed unusually red sunrises and sunsets and milky sunshine and haze recently, it’s caused by sun rays being bent by smoke particles in the air, according to meteorologists.

The Minnesota Pollution Control Agency reported Monday that upper level winds will bring more elevated smoke from wildfires in Idaho and Montana to the region this week. Upper level smoke was visible across southern and central Minnesota.

The smoke is not expected to mix down to the ground, according to the MPCA.

Air quality remained in the green (good) category statewide Tuesday, except for an egg-shaped region extending from near Virginia to Ely.

Lingering smoke from Canadian fires was forecast to be pulled to the ground in northern Minnesota Tuesday. Air quality was forecast to reach the yellow (moderate) category across the northern third of Minnesota.

Winds will become southerly across most of the state Wednesday, causing the smoke to lift out of the state in most areas except northwestern Minnesota.

A Wednesday warmup may elevate ozone in the southwest corner of the state.

By Thursday, all smoke should have cleared northern Minnesota. Southern Minnesota, however, could see moderate air quality due to ozone from unseasonably warm temperatures.

Minnesota air quality numbers are determined by hourly measurements of fine particles, ground-level ozone, sulfur and nitrogen dioxide and carbon monoxide.

No air quality alerts were issued Tuesday. The alerts mean current or forecast conditions can be harmful to those sensitive to air pollution, including people with heart or lung disease, older people, children, and people exerting themselves in prolonged, intensive activities.

Air quality alerts were usually driven by weather that increase the rate at which air pollutants are formed or accumulate in the air.

In recent years, more wildfires are burning bigger and hotter in the western U.S. and central and western Canada. Changes in climate create warmer, drier conditions, more severe droughts and a longer fire season, all of which are boosting increases in wildfire number and severity, according to the Center for Climate and Energy Solutions.

“Mega-fires” like those that have devastated California and are now blanketing Western states like Idaho are expected to continue.

Short-term and long-term exposure to air pollutants can cause a variety of health problems. For those with asthma or chronic obstructive pulmonary disease (COPD/emphysema or chronic bronchitis), air pollution can make it harder to breathe, trigger asthma attacks, or cause wheezing or coughing.

Air pollution increases the risk of respiratory infections, heart disease, strokes and lung cancer. It also more severely affects people who are already ill.

Those most at risk of health problems related to air pollution are people with lung diseases, infants and young children, those who work or exercise outdoors, adults 65 and older, those with a cardiovascular disease, who smoke or are exposed to secondhand smoke, high exposure to contaminated air and who spend a lot of time near busy roads.

For more information, visit pca.state.mn.us.

(Fritz Busch can be emailed at fbusch@nujournal.com.)