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Illinois air quality today

Updated · LIVE · 2 metros tracked

Across the 2 Illinois metros we measure, air is worst right now in Peoria at AQI 36 (Good) and cleanest in Chicago at AQI 30.

Every Illinois metro we track

#MetroAQIUV nowDominant
1 Peoriano page yet 36Good 4.7 PM2.5
2 Chicago 30Good 6 O3

Sun over Illinois today

The strongest UV in Illinois today is 7 (High) in Chicago, arriving around 1pm local time. The mildest of the 2 metros we model here peaks at 7 in Peoria.

7 Chicago 1pm7 Peoria 1pm

UV is modelled, not measured — unlike the AQI above it, which comes off an instrument. Hour by hour in Chicago →

What stands behind these Illinois numbers

2 of the 2 metros here report from a named regulatory monitor — Chicago, Peoria. The dominant pollutant across Illinois today is O3 in some metros, PM2.5 in others.

We track 2 metropolitan areas in Illinois, not the whole state, and 1 of them has a page of its own. There is no state-wide average here on purpose: averaging 2 metros into one figure would invent a value for all the ground between them. How we measure, and what we refuse to estimate →

Neighbouring states

Smoke and inversions do not stop at a state line, so when Illinois looks wrong the answer is often next door.

IndianaIowaKentuckyMissouriWisconsin
Worst air in the US right nowHow Illinois compares against every metro we track What the number meansEPA bands, and where “unhealthy for everyone” starts

Updated