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AirHistory

Air Quality in Illinois

10-year air quality trends for 23 monitored areas in Illinois.

See full Illinois air quality rankings →
23
Cities
45
Avg AQI (5yr)
2
Improving
3
Stable
18
Worsening

All Monitored Areas in Illinois

Clark, Illinois

Clark County · AQI 34 (5yr avg) · Improving · Ozone

B

Macoupin, Illinois

Macoupin County · AQI 33 (5yr avg) · Improving · Ozone

B

Jo Daviess, Illinois

Jo Daviess County · AQI 34 (5yr avg) · Stable · Ozone

B

Effingham, Illinois

Effingham County · AQI 39 (5yr avg) · Stable · Ozone

B

Adams, Illinois

Adams County · AQI 40 (5yr avg) · Worsening · Ozone

C

Randolph, Illinois

Randolph County · AQI 45 (5yr avg) · Stable · PM2.5

C

Peoria, Illinois

Peoria County · AQI 47 (5yr avg) · Stable · PM2.5

C

Champaign, Illinois

Champaign County · AQI 45 (5yr avg) · Worsening · PM2.5

C

Hamilton, Illinois

Hamilton County · AQI 46 (5yr avg) · Worsening · PM2.5

C

Jersey, Illinois

Jersey County · AQI 46 (5yr avg) · Worsening · PM2.5

C

Macon, Illinois

Macon County · AQI 49 (5yr avg) · Worsening · PM2.5

C

Will, Illinois

Will County · AQI 51 (5yr avg) · Stable · PM2.5

C

Lake, Illinois

Lake County · AQI 40 (5yr avg) · Worsening · Ozone

C

McHenry, Illinois

McHenry County · AQI 49 (5yr avg) · Worsening · PM2.5

C

Saint Clair, Illinois

Saint Clair County · AQI 50 (5yr avg) · Worsening · PM2.5

C

Kane, Illinois

Kane County · AQI 43 (5yr avg) · Worsening · Ozone

C

Madison, Illinois

Madison County · AQI 55 (5yr avg) · Worsening · PM2.5

C

Cook, Illinois

Cook County · AQI 57 (5yr avg) · Stable · PM2.5

D

DuPage, Illinois

DuPage County · AQI 49 (5yr avg) · Worsening · PM2.5

D

McLean, Illinois

McLean County · AQI 48 (5yr avg) · Worsening · PM2.5

D

Sangamon, Illinois

Sangamon County · AQI 46 (5yr avg) · Worsening · PM2.5

D

Rock Island, Illinois

Rock Island County · AQI 47 (5yr avg) · Worsening · PM2.5

D

Winnebago, Illinois

Winnebago County · AQI 48 (5yr avg) · Worsening · Ozone

D
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Frequently Asked Questions

Illinois has 23 monitored areas with an average 5-year AQI of 45 and an average Air Quality Grade of C. 2 cities are improving, 18 are worsening, and 3 are stable.

Clark, Illinois has the best Air Quality Grade (B) in Illinois with a 5-year average AQI of 34.

Of 23 monitored areas in Illinois, 2 are showing improving trends, 18 are worsening, and 3 remain stable over the past decade.

Sources: EPA Air Quality System (AQS)
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