COLUMBUS, Ohio (WCMH) – When western wildfire smoke turned the Columbus sun hazy last month, it was not a one-off event. A new analysis shows West Coast smoke is already impacting Ohio skies, and local experts say worsening fire seasons thousands of miles away could hurt health and agriculture in central Ohio.

Most of Ohio sees 4-6 weeks of smoky days per year, according to a nationwide analysis published in September by journalists at California’s public radio stations and researchers at Stanford University.

They examined more than 10 years of satellite data from the National Oceanic and Atmospheric Administration and found more western wildfire smoke is already showing up in the Columbus area compared to a decade ago.

KCRW wildfire smoke map screenshot
Most of Ohio sees between four and six weeks of wildfire smoke per year. (Screenshot via KCRW)

“On average, the wildfire season is being extended longer and wildfires (are) burning later into the night because of hotter and drier conditions,” said NBC4 meteorologist Ben Gelber, alluding to a 20-year megadrought drying western forests and fueled in part by human-caused climate change.

Most of central Ohio averaged more than 30 smoky days between 2016 and 2020, which NPR/Stanford defined as days when a plume of wildfire smoke is over the region. That’s an increase of about a week over 2009-2013.

Parts of far northwestern Ohio currently see as many as 42 smoky days a year, while some communities on the West Virginia border see slightly less than 30.

Selected ZIPAvg. smoky days ’09-’13Avg. smoky days ’16-’20
43219 (John Glenn Airport)25 days34 days
43215 (Downtown Columbus)24 days34 days
43055 (Newark)25 days33 days
43015 (Delaware)27 days36 days
43130 (Lancaster)24 days32 days
43302 (Marion)29 days37 days
45701 (Athens)21 days31 days
43518/43543 (Williams Co.; most in Ohio)38 days42 days
Source: Analysis of NOAA satellite imagery by journalists with NPR’s California Newsroom and researchers at Stanford University.

Far away fires, local health burden

The biggest effect in Ohio of all this smoke drifting through the upper atmosphere is a dimmed sun and hazy sky as smoke particles scatter sunlight.

“But occasionally, if we have high pressure and sinking air,” Gelber said, “we may see some of that smoke get closer to the ground. And we saw that on a few days this summer.”

When smoke wafted through Columbus skies in mid-September, the Air Quality Index hit a “moderate” value of 58, which the U.S. Environmental Protection Agency says is risky for people “unusually sensitive to air pollution.”

EPA Air Quality Index AQI table
The U.S. EPA’s Air Quality Index (AQI) table. (Screenshot via

Smoke’s main contributor is a pollutant called PM 2.5 (particulate matter of less than 2.5 microns).

“That size of a particle can go deep into your lungs and quite possibly go directly into your bloodstream,” said John Franks, a National Weather Service meteorologist based in Wilmington. He also serves the NWS as an incident meteorologist providing wildfire crews with on-site weather forecasting.

Franks said we already breathe in some PM 2.5 particles, since they include pollen, dust and cigarette smoke, but wildfire smoke can up the count.

“If you’re in a sensitive group, you should know about this,” Franks said, such as people with breathing problems like COPD.

The EPA includes in that group people with heart disease and diabetes, plus children and the elderly. And, Gelber said, “we all could be affected in terms of air quality by an increase in allergy symptoms: itchy eyes, watery eyes.”

This fire season has burned more than 6.4 million acres in the U.S., according to the National Interagency Fire Center. Nearly 2 million acres have burned in California alone, which has seen nine of its 20 largest fires in the past two fire seasons and 18 of its largest 20 since 2000:

The Dixie Fire – California’s biggest blaze this year and its second-biggest ever – has eclipsed 963,000 acres after starting in July. It contributed to hazy days in Columbus in July and September.

The area where Dixie originated, for example, has seen an increase of 12 days since 1973 when hot, dry and windy conditions are ideal for fires to start, according to a Climate Central analysis NBC4 reported on last month.

“The risk of declining air quality for small groups of days in the coming summers from wildfires, which was a rarer event in previous decades, is certainly something that we will have to monitor,” Gelber said.

Haze could affect cash crops

Hazier skies mean less sunshine, which is less energy for crops to grow. Ohio’s two major cash crops – corn and soybeans – especially rely on sunshine, and the state ranks 8th and 7th respectively in production according to the U.S. Department of Agriculture.

“In general, the more light you have available during the growing season, the more photosynthesis potential you have and the higher your yield potential can be,” said Alex Lindsey, an associate professor of crop ecophysiology at The Ohio State University.

Unfortunately, corn’s growing season in Ohio (late spring to early fall) lines up with when the Western U.S. usually sees its worst fires (summer to early fall).

Lindsey said sunlight for plants is usually discussed as “photosynthetically active light particles.” A sunny day can give plants 1,800-2,200 of these particles, but that goes down to just 100-400 on a cloudy day, he said. A hazy day is somewhere in the middle but “still a substantial reduction compared to a full sun day.”

Local weather station data, Lindsey said, shows light for this past growing season was “slightly below” their five-year average, and the smoke from summer’s western wildfires is partly to blame.

“The haze, mixed with variable clouds and cloud cover, all of those things would factor into lower intercepted light or lower available light levels that we witnessed this past growing season,” he said. “But haze definitely played a role in that.”

Lindsey noted, though, “it’s a possibility” that local corn and soybean yields could thus be lower than expected in this fall harvest, but many other things affect crop yields, like temperatures, rainfall and water in the soil. Plus, plants can position themselves to collect more light.

“Even if there is enough light, with other limiting factors, the plant may not actually realize its full potential,” he said. “But anytime you limit the amount of sunlight, you’re inherently limiting the top-end yield you might be able to experience if everything else goes perfectly for that growing season.”

Smoke and Ohio in a warmer future

Wildfires are likely to get worse as the western megadrought continues and climate change further parches the region because heat-trapping gases like carbon dioxide warm the atmosphere.

“It’s an ever-cascading negative feedback loop there,” Franks said. Wildfires worsened by climate change blaze more carbon into the atmosphere, worsening climate change.

“It’s the extremes,” he said. “… Those large-scale events that wouldn’t have happened on a typical basis are happening with more frequency.”

Smoke dissipates the farther east it travels, so it makes sense that Ohio sees comparatively less of it, about 4-6 weeks a year per the NPR/Stanford analysis. But even Midwest states like Iowa and Minnesota see 8-10 weeks a year of wildfire smoke, possibly an indicator of a future Ohio.

Gelber said it’s hard to predict the rainfall that the West will see over the next decade, but the trend is drought, which means more smoke.

“If that pattern continues, which is not certain but more likely in a warmer environment, then more smoky days would be expected in the Ohio Valley downwind of wildfires,” he said, “whether it’s an increasing number of wildfires or simply an extension of the wildfire season.”

Franks said the people most at risk of wildfire-worsened air quality in Ohio should be aware of precautions now, such as keeping doors closed and installing HEPA filters. The latter can filter 99.97% of airborne particles smaller than 0.3 microns.

“If you are in a nursing home or you’re employed at a nursing home, these are the types of things that you need to be working on ahead of time,” he said.

As for crops, OSU’s Lindsey noted the impact of more haze subduing sunlight would likely hurt corn more than soybeans, because corn can use more light to maximize its growth and soybean plants max out their light intake at a “slightly lower intensity.”

But should farmers start tempering their expectations because of the amount of wildfire haze Ohio sees now, which is still among the lowest in the Midwest?

“Potentially, the top-end yield that we’ve realized may be affected by the haze,” Lindsey said. “But at this point, I don’t think it’s reducing sunlight enough to reduce yield where it’s going to be noticeable. If it continues, we may end up experiencing something more along those lines.”