Illinois air quality

Bethany, Illinois Air Quality

Moultrie County39.646, -88.738

The nearest monitor to Bethany, at DECATUR, 18 miles away, measured an index of 44 at Sun, 1:00 PM CDT, which is Good for ground-level ozone. Illinois EPA forecasts Moderate for Decatur today and Good tomorrow. NOAA’s analysts drew medium wildfire smoke over the town today.

Measured now
44 · Good
Today
— · Moderate
Tomorrow
— · Good
Pollutant
Ozone

Fine particles on the map

Forecast fine particulate matter from NOAA’s National Air Quality Forecast Capability over Bethany, Illinois. Open it for the live map, where it pans and zooms.

Forecast fine particulate matter from NOAA’s National Air Quality Forecast Capability over Bethany, Illinois Open the live map with the particulate forecast

Map layer from NOAA National Air Quality Forecast Capability. Boundaries from the Iowa Environmental Mesonet.

Alerts in force

An Air Quality Alert is issued by the National Weather Service on behalf of a state or local agency when pollution is expected to reach a level that harms health. An Air Stagnation Advisory means the air will not move enough to clear what is already in it.

None are in force near Bethany right now. All Illinois warnings.

Now

Good

Nearest monitor
DECATUR, 18 miles away (site 171150013)
Index measured
44 · Good
Measured at
Sun, 1:00 PM CDT
Fine particles
4.7 µg/m³
Ozone
51 ppb
Reporting area
Decatur, IL, 19 miles away
Reported by
Illinois EPA
Area index
44 · Good

Measured, not modeled. AirNow observations are preliminary until the operating agency certifies them, which happens months later.

Today and tomorrow

Illinois EPA's own forecast for Decatur, written by a forecaster rather than read off a model.

DayCategoryIndexPollutant
TodayModeratePM2.5
TomorrowGoodPM2.5

Hour by hour

NOAA’s National Air Quality Forecast Capability, bias-corrected against monitors, for this town’s own coordinate. The worst hour ahead is an index of 54, Moderate, around Sun, 11:00 AM CDT, from the run issued Sun, 7:00 AM CDT. This is a model, not a measurement.

HourIndexCategoryPM2.5Ozone
Sun, 9:00 AM CDT51Moderate10
Sun, 10:00 AM CDT53Moderate11.1
Sun, 11:00 AM CDT54Moderate11.4
Sun, 12:00 PM CDT53Moderate10.2
Sun, 1:00 PM CDT53Moderate9.6
Sun, 2:00 PM CDT52Moderate8.9
Sun, 3:00 PM CDT48Good7.134.1
Sun, 4:00 PM CDT41Good6.338.6
Sun, 5:00 PM CDT38Good6.141.8
Sun, 6:00 PM CDT40Good6.143.3
Sun, 7:00 PM CDT40Good3.843.1
Sun, 8:00 PM CDT38Good2.641.9
Sun, 9:00 PM CDT37Good440.2
Sun, 10:00 PM CDT34Good5.637.7
Sun, 11:00 PM CDT31Good6.234.9
Mon, 12:00 AM CDT37Good7.931.4
Mon, 1:00 AM CDT41Good8.328
Mon, 2:00 AM CDT39Good6.725.5
Mon, 3:00 AM CDT35Good5.623.8
Mon, 4:00 AM CDT33Good5.822
Mon, 5:00 AM CDT32Good5.520.2
Mon, 6:00 AM CDT29Good4.919.1
Mon, 7:00 AM CDT27Good4.618.5
Mon, 8:00 AM CDT28Good5.318.3
Mon, 9:00 AM CDT32Good6.618.3
Mon, 10:00 AM CDT34Good6.718.4
Mon, 11:00 AM CDT37Good7.518.4
Mon, 12:00 PM CDT37Good6.519.1
Mon, 1:00 PM CDT34Good5.820.3
Mon, 2:00 PM CDT32Good5.222
Mon, 3:00 PM CDT32Good5.524
Mon, 4:00 PM CDT32Good5.826
Mon, 5:00 PM CDT29Good4.527.8
Mon, 6:00 PM CDT27Good3.529
Mon, 7:00 PM CDT27Good2.629.1
Mon, 8:00 PM CDT26Good2.528.5
Mon, 9:00 PM CDT25Good1.827.5
Mon, 10:00 PM CDT24Good326.3
Mon, 11:00 PM CDT22Good3.724.6
Tue, 12:00 AM CDT20Good3.722.7
Tue, 1:00 AM CDT19Good3.421
Tue, 2:00 AM CDT18Good2.719.6
Tue, 3:00 AM CDT18Good2.619.4
Tue, 4:00 AM CDT18Good2.719.7
Tue, 5:00 AM CDT18Good3.520
Tue, 6:00 AM CDT18Good3.419.4
Tue, 7:00 AM CDT20Good4.119.4
Tue, 8:00 AM CDT23Good4.919.3
Tue, 9:00 AM CDT27Good5.719.4
Tue, 10:00 AM CDT27Good4.919.7
Tue, 11:00 AM CDT26Good4.620.2
Tue, 12:00 PM CDT24Good4.120.9
Tue, 1:00 PM CDT26Good4.922.6
Tue, 2:00 PM CDT31Good6.425
Tue, 3:00 PM CDT32Good6.227.3
Tue, 4:00 PM CDT33Good6.129.8
Tue, 5:00 PM CDT31Good5.132.1
Tue, 6:00 PM CDT31Good4.534.2
Tue, 7:00 PM CDT32Good3.735.6
Tue, 8:00 PM CDT33Good1.936
Tue, 9:00 PM CDT32Good3.835.5
Tue, 10:00 PM CDT31Good534.3
Tue, 11:00 PM CDT30Good4.932.5
Wed, 12:00 AM CDT28Good3.830.7
Wed, 1:00 AM CDT27Good4.329
Wed, 2:00 AM CDT25Good4.827.7
Wed, 3:00 AM CDT27Good5.426.8
Wed, 4:00 AM CDT29Good5.626.2
Wed, 5:00 AM CDT32Good6.225.2
Wed, 6:00 AM CDT31Good5.424.1
Wed, 7:00 AM CDT29Good523.4

Fine particles in micrograms per cubic meter, ozone in parts per billion as an 8-hour average. The index for each hour is EPA’s: the ozone figure is already the 8-hour average the ozone index is defined on, and the particle figure is run through EPA’s NowCast, which is how an hourly PM2.5 concentration becomes an index.

Smoke

NOAA’s Hazard Mapping System analysts drew medium smoke over Bethany in satellite imagery today (Sun, 7:00 AM CDT to Sun, 10:00 AM CDT). That is smoke seen from above; it is not always smoke at ground level.

NOAA’s model forecasts near-surface smoke peaking at 1.1 µg/m³ around Sun, 2:00 PM CDT.

Smoke on the radar over Bethany

What this means

Good

Air quality is satisfactory, and air pollution poses little or no risk.

Who is affected
Nobody is expected to be affected.
What to do
It is a good day to be outside.
Index range
0 to 50

Category descriptions are the Environmental Protection Agency’s own.

What these numbers are. An index beside a monitor’s name is a measurement, published hourly by AirNow and preliminary until the operating agency certifies it. A category for today or tomorrow is a state or local agency forecaster’s own forecast for a reporting area. An hourly index is NOAA’s air quality model on a five-kilometer grid, not a reading from any instrument. Where a town has no monitor within reach, only the model figures appear, and the page says so.

Nearby

The nearest towns with a page of their own, closest first.

Weather forecast for BethanyWarnings in Moultrie CountyLive radar over BethanyIllinois air quality

Sources

Observations and daily forecasts from AirNow, the US Environmental Protection Agency’s program with NOAA, the National Park Service, NASA, tribal, state and local agencies. Hourly forecasts from NOAA’s National Air Quality Forecast Capability. Smoke analysis from NOAA’s Hazard Mapping System. Alerts from the National Weather Service. Index categories and breakpoints are EPA’s, as revised in 2024.