Chester, Illinois, United States Historical Air Quality Analysis
Dive into detailed Air Quality Insights with historical data, monthly patterns, and yearly trends at your fingertips!
Good
050
Moderate
100
Poor
150
Unhealthy
200
Severe
300
Hazardous
301+
August Air Quality Analysis
Chester, Illinois, United States
2021
2022
2023
2024
2025
AQI
.
Days
AQI Trends: Highest and Lowest
Highest AQI recorded on
1st Aug 2021
97AQILowest AQI recorded on
27th Aug 2023
21AQISame Day Analysis (8th August ):
On this day, AQI across the 5 years varied significantly: 2025 ranks 2nd highest AQI at 52 of Moderate air quality, showing improvement over 2021 on the same day.
Download 2024 Annual Data
World Air Quality Report
Day & Night AQI Trend: 8th Aug - 9th Aug 2025
Chester, Illinois, United States
AQI
Day
Night
.
5 AM8th Aug 2025
8 PM
4 AM9th Aug 2025
Day time
Avg. Highest Time
10AM8th Aug
40AQI
Avg. Lowest Time
6AM8th Aug
35AQI
Night time
Avg. Highest Time
9PM8th Aug
38AQI
Avg. Lowest Time
4AM9th Aug
35AQI
In the last 24 hours,
Chester's AQI reached its highest point of 40 at 10 AM during the Day, while the lowest point, 35, was recorded at 4 AM during the Night between 8th Aug and 9th Aug 2025.
Day & Night AQI Trend : Jul - Aug 2025
Chester, Illinois, United States
JulAug
10th - 11th11th - 12th12th - 13th13th - 14th14th - 15th15th - 16th16th - 17th17th - 18th18th - 19th19th - 20th20th - 21st21st - 22nd22nd - 23rd23rd - 24th24th - 25th25th - 26th26th - 27th27th - 28th28th - 29th29th - 30th30th - 31st31st - 01st01st - 02nd02nd - 03rd03rd - 04th04th - 05th05th - 06th06th - 07th07th - 08th08th - 09th09th
Day
Night
10th Jul 2025385 AMAQI
10th Jul 2025376 AMAQI
10th Jul 2025367 AMAQI
10th Jul 2025378 AMAQI
10th Jul 2025399 AMAQI
10th Jul 20254010 AMAQI
10th Jul 20254011 AMAQI
10th Jul 20254212 PMAQI
10th Jul 2025431 PMAQI
10th Jul 2025452 PMAQI
10th Jul 2025433 PMAQI
10th Jul 2025424 PMAQI
10th Jul 2025425 PMAQI
10th Jul 2025416 PMAQI
10th Jul 2025397 PMAQI
10th Jul 2025388 PMAQI
10th Jul 2025399 PMAQI
10th Jul 20253910 PMAQI
10th Jul 20253811 PMAQI
11th Jul 20253912 AMAQI
11th Jul 2025401 AMAQI
11th Jul 2025382 AMAQI
11th Jul 2025393 AMAQI
11th Jul 2025424 AMAQI
27°C19/34°C
11th Jul 2025435 AMAQI
11th Jul 2025446 AMAQI
11th Jul 2025457 AMAQI
11th Jul 2025458 AMAQI
11th Jul 2025459 AMAQI
11th Jul 20254410 AMAQI
11th Jul 20254511 AMAQI
11th Jul 20254512 PMAQI
11th Jul 2025451 PMAQI
11th Jul 2025442 PMAQI
11th Jul 2025443 PMAQI
11th Jul 2025424 PMAQI
11th Jul 2025415 PMAQI
11th Jul 2025416 PMAQI
11th Jul 2025437 PMAQI
11th Jul 2025438 PMAQI
11th Jul 2025419 PMAQI
11th Jul 20254210 PMAQI
11th Jul 20254211 PMAQI
12th Jul 20254112 AMAQI
12th Jul 2025411 AMAQI
12th Jul 2025392 AMAQI
12th Jul 2025383 AMAQI
12th Jul 2025374 AMAQI
28°C21/36°C
12th Jul 2025355 AMAQI
12th Jul 2025336 AMAQI
12th Jul 2025367 AMAQI
12th Jul 2025368 AMAQI
12th Jul 2025369 AMAQI
12th Jul 20254010 AMAQI
12th Jul 20254211 AMAQI
12th Jul 20254112 PMAQI
12th Jul 2025411 PMAQI
12th Jul 2025402 PMAQI
12th Jul 2025403 PMAQI
12th Jul 2025394 PMAQI
12th Jul 2025385 PMAQI
12th Jul 2025366 PMAQI
12th Jul 2025377 PMAQI
12th Jul 2025388 PMAQI
12th Jul 2025389 PMAQI
12th Jul 20253710 PMAQI
12th Jul 20253911 PMAQI
13th Jul 20253812 AMAQI
13th Jul 2025361 AMAQI
13th Jul 2025332 AMAQI
13th Jul 2025333 AMAQI
13th Jul 2025324 AMAQI
27°C24/30°C
13th Jul 2025325 AMAQI
13th Jul 2025326 AMAQI
13th Jul 2025347 AMAQI
13th Jul 2025348 AMAQI
13th Jul 2025349 AMAQI
13th Jul 20253110 AMAQI
13th Jul 20253011 AMAQI
13th Jul 20253512 PMAQI
13th Jul 2025341 PMAQI
13th Jul 2025362 PMAQI
13th Jul 2025333 PMAQI
13th Jul 2025334 PMAQI
13th Jul 2025335 PMAQI
13th Jul 2025336 PMAQI
13th Jul 2025347 PMAQI
13th Jul 2025348 PMAQI
13th Jul 2025339 PMAQI
13th Jul 20253210 PMAQI
13th Jul 20253311 PMAQI
14th Jul 20253212 AMAQI
14th Jul 2025321 AMAQI
14th Jul 2025312 AMAQI
14th Jul 2025323 AMAQI
14th Jul 2025324 AMAQI
25°C22/33°C
14th Jul 2025325 AMAQI
14th Jul 2025326 AMAQI
14th Jul 2025337 AMAQI
14th Jul 2025338 AMAQI
14th Jul 2025349 AMAQI
14th Jul 20253510 AMAQI
14th Jul 20253711 AMAQI
14th Jul 20254112 PMAQI
14th Jul 2025411 PMAQI
14th Jul 2025402 PMAQI
14th Jul 2025393 PMAQI
14th Jul 2025384 PMAQI
14th Jul 2025385 PMAQI
14th Jul 2025376 PMAQI
14th Jul 2025367 PMAQI
14th Jul 2025358 PMAQI
14th Jul 2025339 PMAQI
14th Jul 20253210 PMAQI
14th Jul 20253111 PMAQI
15th Jul 20252912 AMAQI
15th Jul 2025281 AMAQI
15th Jul 2025262 AMAQI
15th Jul 2025283 AMAQI
15th Jul 2025274 AMAQI
24°C21/28°C
15th Jul 2025285 AMAQI
15th Jul 2025296 AMAQI
15th Jul 2025297 AMAQI
15th Jul 2025288 AMAQI
15th Jul 2025289 AMAQI
15th Jul 20252910 AMAQI
15th Jul 20253111 AMAQI
15th Jul 20253212 PMAQI
15th Jul 2025321 PMAQI
15th Jul 2025342 PMAQI
15th Jul 2025353 PMAQI
15th Jul 2025344 PMAQI
15th Jul 2025345 PMAQI
15th Jul 2025346 PMAQI
15th Jul 2025327 PMAQI
15th Jul 2025318 PMAQI
15th Jul 2025329 PMAQI
15th Jul 20253210 PMAQI
15th Jul 20253211 PMAQI
16th Jul 20253212 AMAQI
16th Jul 2025311 AMAQI
16th Jul 2025322 AMAQI
16th Jul 2025313 AMAQI
16th Jul 2025314 AMAQI
26°C21/30°C
16th Jul 2025315 AMAQI
16th Jul 2025316 AMAQI
16th Jul 2025337 AMAQI
16th Jul 2025328 AMAQI
16th Jul 2025339 AMAQI
16th Jul 20253410 AMAQI
16th Jul 20253511 AMAQI
16th Jul 20253512 PMAQI
16th Jul 2025351 PMAQI
16th Jul 2025362 PMAQI
16th Jul 2025363 PMAQI
16th Jul 2025344 PMAQI
16th Jul 2025355 PMAQI
16th Jul 2025356 PMAQI
16th Jul 2025357 PMAQI
16th Jul 2025348 PMAQI
16th Jul 2025369 PMAQI
16th Jul 20253710 PMAQI
16th Jul 20253511 PMAQI
17th Jul 20253212 AMAQI
17th Jul 2025311 AMAQI
17th Jul 2025292 AMAQI
17th Jul 2025283 AMAQI
17th Jul 2025274 AMAQI
28°C22/36°C
17th Jul 2025285 AMAQI
17th Jul 2025276 AMAQI
17th Jul 2025297 AMAQI
17th Jul 2025308 AMAQI
17th Jul 2025289 AMAQI
17th Jul 20252910 AMAQI
17th Jul 20253211 AMAQI
17th Jul 20253512 PMAQI
17th Jul 2025381 PMAQI
17th Jul 2025372 PMAQI
17th Jul 2025373 PMAQI
17th Jul 2025364 PMAQI
17th Jul 2025355 PMAQI
17th Jul 2025336 PMAQI
17th Jul 2025347 PMAQI
17th Jul 2025338 PMAQI
17th Jul 2025339 PMAQI
17th Jul 20253110 PMAQI
17th Jul 20253011 PMAQI
18th Jul 20252912 AMAQI
18th Jul 2025271 AMAQI
18th Jul 2025232 AMAQI
18th Jul 2025223 AMAQI
18th Jul 2025224 AMAQI
27°C23/34°C
18th Jul 2025215 AMAQI
18th Jul 2025226 AMAQI
18th Jul 2025257 AMAQI
18th Jul 2025258 AMAQI
18th Jul 2025289 AMAQI
18th Jul 20252810 AMAQI
18th Jul 20252811 AMAQI
18th Jul 20252912 PMAQI
18th Jul 2025301 PMAQI
18th Jul 2025282 PMAQI
18th Jul 2025273 PMAQI
18th Jul 2025274 PMAQI
18th Jul 2025275 PMAQI
18th Jul 2025276 PMAQI
18th Jul 2025267 PMAQI
18th Jul 2025268 PMAQI
18th Jul 2025299 PMAQI
18th Jul 20252810 PMAQI
18th Jul 20252811 PMAQI
19th Jul 20252712 AMAQI
19th Jul 2025281 AMAQI
19th Jul 2025292 AMAQI
19th Jul 2025313 AMAQI
19th Jul 2025304 AMAQI
27°C23/32°C
19th Jul 2025265 AMAQI
19th Jul 2025286 AMAQI
19th Jul 2025307 AMAQI
19th Jul 2025298 AMAQI
19th Jul 2025319 AMAQI
19th Jul 20253110 AMAQI
19th Jul 20253411 AMAQI
19th Jul 20253212 PMAQI
19th Jul 2025321 PMAQI
19th Jul 2025322 PMAQI
19th Jul 2025333 PMAQI
19th Jul 2025324 PMAQI
19th Jul 2025335 PMAQI
19th Jul 2025326 PMAQI
19th Jul 2025317 PMAQI
19th Jul 2025318 PMAQI
19th Jul 2025319 PMAQI
19th Jul 20253110 PMAQI
19th Jul 20253111 PMAQI
20th Jul 20253112 AMAQI
20th Jul 2025331 AMAQI
20th Jul 2025352 AMAQI
20th Jul 2025353 AMAQI
20th Jul 2025364 AMAQI
27°C23/32°C
20th Jul 2025365 AMAQI
20th Jul 2025386 AMAQI
20th Jul 2025397 AMAQI
20th Jul 2025388 AMAQI
20th Jul 2025399 AMAQI
20th Jul 20253710 AMAQI
20th Jul 20253511 AMAQI
20th Jul 20253412 PMAQI
20th Jul 2025341 PMAQI
20th Jul 2025342 PMAQI
20th Jul 2025363 PMAQI
20th Jul 2025374 PMAQI
20th Jul 2025375 PMAQI
20th Jul 2025376 PMAQI
20th Jul 2025357 PMAQI
20th Jul 2025358 PMAQI
20th Jul 2025369 PMAQI
20th Jul 20253610 PMAQI
20th Jul 20253611 PMAQI
21st Jul 20253512 AMAQI
21st Jul 2025331 AMAQI
21st Jul 2025332 AMAQI
21st Jul 2025313 AMAQI
21st Jul 2025304 AMAQI
30°C24/36°C
21st Jul 2025275 AMAQI
21st Jul 2025276 AMAQI
21st Jul 2025287 AMAQI
21st Jul 2025278 AMAQI
21st Jul 2025289 AMAQI
21st Jul 20252910 AMAQI
21st Jul 20253411 AMAQI
21st Jul 20253512 PMAQI
21st Jul 2025381 PMAQI
21st Jul 2025392 PMAQI
21st Jul 2025383 PMAQI
21st Jul 2025414 PMAQI
21st Jul 2025405 PMAQI
21st Jul 2025406 PMAQI
21st Jul 2025347 PMAQI
21st Jul 2025338 PMAQI
21st Jul 2025399 PMAQI
21st Jul 20253610 PMAQI
21st Jul 20253611 PMAQI
22nd Jul 20253712 AMAQI
22nd Jul 2025401 AMAQI
22nd Jul 2025432 AMAQI
22nd Jul 2025413 AMAQI
22nd Jul 2025394 AMAQI
27°C23/31°C
22nd Jul 2025385 AMAQI
22nd Jul 2025366 AMAQI
22nd Jul 2025367 AMAQI
22nd Jul 2025368 AMAQI
22nd Jul 2025379 AMAQI
22nd Jul 20253910 AMAQI
22nd Jul 20253911 AMAQI
22nd Jul 20254012 PMAQI
22nd Jul 2025401 PMAQI
22nd Jul 2025412 PMAQI
22nd Jul 2025423 PMAQI
22nd Jul 2025444 PMAQI
22nd Jul 2025435 PMAQI
22nd Jul 2025436 PMAQI
22nd Jul 2025427 PMAQI
22nd Jul 2025428 PMAQI
22nd Jul 2025429 PMAQI
22nd Jul 20254010 PMAQI
22nd Jul 20253911 PMAQI
23rd Jul 20253912 AMAQI
23rd Jul 2025361 AMAQI
23rd Jul 2025332 AMAQI
23rd Jul 2025333 AMAQI
23rd Jul 2025324 AMAQI
28°C23/34°C
23rd Jul 2025325 AMAQI
23rd Jul 2025336 AMAQI
23rd Jul 2025357 AMAQI
23rd Jul 2025348 AMAQI
23rd Jul 2025349 AMAQI
23rd Jul 20253510 AMAQI
23rd Jul 20253611 AMAQI
23rd Jul 20253812 PMAQI
23rd Jul 2025391 PMAQI
23rd Jul 2025392 PMAQI
23rd Jul 2025393 PMAQI
23rd Jul 2025394 PMAQI
23rd Jul 2025425 PMAQI
23rd Jul 2025426 PMAQI
23rd Jul 2025397 PMAQI
23rd Jul 2025388 PMAQI
23rd Jul 2025409 PMAQI
23rd Jul 20254110 PMAQI
23rd Jul 20253811 PMAQI
24th Jul 20253712 AMAQI
24th Jul 2025351 AMAQI
24th Jul 2025352 AMAQI
24th Jul 2025353 AMAQI
24th Jul 2025364 AMAQI
30°C25/36°C
24th Jul 2025355 AMAQI
24th Jul 2025366 AMAQI
24th Jul 2025367 AMAQI
24th Jul 2025378 AMAQI
24th Jul 2025369 AMAQI
24th Jul 20253810 AMAQI
24th Jul 20254011 AMAQI
24th Jul 20254312 PMAQI
24th Jul 2025421 PMAQI
24th Jul 2025432 PMAQI
24th Jul 2025433 PMAQI
24th Jul 2025434 PMAQI
24th Jul 2025425 PMAQI
24th Jul 2025436 PMAQI
24th Jul 2025417 PMAQI
24th Jul 2025418 PMAQI
24th Jul 2025429 PMAQI
24th Jul 20254310 PMAQI
24th Jul 20254211 PMAQI
25th Jul 20254312 AMAQI
25th Jul 2025431 AMAQI
25th Jul 2025432 AMAQI
25th Jul 2025433 AMAQI
25th Jul 2025444 AMAQI
30°C25/37°C
25th Jul 2025445 AMAQI
25th Jul 2025446 AMAQI
25th Jul 2025447 AMAQI
25th Jul 2025438 AMAQI
25th Jul 2025449 AMAQI
25th Jul 20254510 AMAQI
25th Jul 20254611 AMAQI
25th Jul 20254612 PMAQI
25th Jul 2025461 PMAQI
25th Jul 2025482 PMAQI
25th Jul 2025493 PMAQI
25th Jul 2025494 PMAQI
25th Jul 2025465 PMAQI
25th Jul 2025476 PMAQI
25th Jul 2025457 PMAQI
25th Jul 2025448 PMAQI
25th Jul 2025419 PMAQI
25th Jul 20254010 PMAQI
25th Jul 20254011 PMAQI
26th Jul 20254012 AMAQI
26th Jul 2025371 AMAQI
26th Jul 2025332 AMAQI
26th Jul 2025323 AMAQI
26th Jul 2025304 AMAQI
29°C25/35°C
26th Jul 2025305 AMAQI
26th Jul 2025306 AMAQI
26th Jul 2025317 AMAQI
26th Jul 2025338 AMAQI
26th Jul 2025359 AMAQI
26th Jul 20253910 AMAQI
26th Jul 20254111 AMAQI
26th Jul 20254012 PMAQI
26th Jul 2025411 PMAQI
26th Jul 2025412 PMAQI
26th Jul 2025433 PMAQI
26th Jul 2025414 PMAQI
26th Jul 2025395 PMAQI
26th Jul 2025396 PMAQI
26th Jul 2025387 PMAQI
26th Jul 2025388 PMAQI
26th Jul 2025399 PMAQI
26th Jul 20254010 PMAQI
26th Jul 20253911 PMAQI
27th Jul 20254112 AMAQI
27th Jul 2025461 AMAQI
27th Jul 2025672 AMAQI
27th Jul 2025683 AMAQI
27th Jul 2025664 AMAQI
29°C25/35°C
27th Jul 2025655 AMAQI
27th Jul 2025616 AMAQI
27th Jul 2025607 AMAQI
27th Jul 2025618 AMAQI
27th Jul 2025619 AMAQI
27th Jul 20255810 AMAQI
27th Jul 20255611 AMAQI
27th Jul 20255512 PMAQI
27th Jul 2025531 PMAQI
27th Jul 2025542 PMAQI
27th Jul 2025533 PMAQI
27th Jul 2025534 PMAQI
27th Jul 2025515 PMAQI
27th Jul 2025496 PMAQI
27th Jul 2025587 PMAQI
27th Jul 2025588 PMAQI
27th Jul 2025479 PMAQI
27th Jul 20254610 PMAQI
27th Jul 20254611 PMAQI
28th Jul 20254512 AMAQI
28th Jul 2025401 AMAQI
28th Jul 2025312 AMAQI
28th Jul 2025313 AMAQI
28th Jul 2025314 AMAQI
29°C24/33°C
28th Jul 2025335 AMAQI
28th Jul 2025356 AMAQI
28th Jul 2025377 AMAQI
28th Jul 2025368 AMAQI
28th Jul 2025379 AMAQI
28th Jul 20253710 AMAQI
28th Jul 20253911 AMAQI
28th Jul 20254012 PMAQI
28th Jul 2025421 PMAQI
28th Jul 2025442 PMAQI
28th Jul 2025413 PMAQI
28th Jul 2025414 PMAQI
28th Jul 2025405 PMAQI
28th Jul 2025416 PMAQI
28th Jul 2025367 PMAQI
28th Jul 2025368 PMAQI
28th Jul 2025409 PMAQI
28th Jul 20253910 PMAQI
28th Jul 20254211 PMAQI
29th Jul 20254412 AMAQI
29th Jul 2025441 AMAQI
29th Jul 2025442 AMAQI
29th Jul 2025463 AMAQI
29th Jul 2025464 AMAQI
31°C25/37°C
29th Jul 2025445 AMAQI
29th Jul 2025456 AMAQI
29th Jul 2025467 AMAQI
29th Jul 2025468 AMAQI
29th Jul 2025469 AMAQI
29th Jul 20254510 AMAQI
29th Jul 20254511 AMAQI
29th Jul 20254512 PMAQI
29th Jul 2025461 PMAQI
29th Jul 2025462 PMAQI
29th Jul 2025463 PMAQI
29th Jul 2025464 PMAQI
29th Jul 2025465 PMAQI
29th Jul 2025456 PMAQI
29th Jul 2025467 PMAQI
29th Jul 2025478 PMAQI
29th Jul 2025459 PMAQI
29th Jul 20254410 PMAQI
29th Jul 20254511 PMAQI
30th Jul 20254512 AMAQI
30th Jul 2025441 AMAQI
30th Jul 2025432 AMAQI
30th Jul 2025453 AMAQI
30th Jul 2025444 AMAQI
30°C25/36°C
30th Jul 2025445 AMAQI
30th Jul 2025466 AMAQI
30th Jul 2025477 AMAQI
30th Jul 2025488 AMAQI
30th Jul 2025479 AMAQI
30th Jul 20254710 AMAQI
30th Jul 20254911 AMAQI
30th Jul 20254912 PMAQI
30th Jul 2025501 PMAQI
30th Jul 2025492 PMAQI
30th Jul 2025493 PMAQI
30th Jul 2025494 PMAQI
30th Jul 2025495 PMAQI
30th Jul 2025496 PMAQI
30th Jul 2025497 PMAQI
30th Jul 2025498 PMAQI
30th Jul 2025479 PMAQI
30th Jul 20254710 PMAQI
30th Jul 20254711 PMAQI
31st Jul 20254612 AMAQI
31st Jul 2025451 AMAQI
31st Jul 2025422 AMAQI
31st Jul 2025423 AMAQI
31st Jul 2025424 AMAQI
29°C23/36°C
31st Jul 2025405 AMAQI
31st Jul 2025426 AMAQI
31st Jul 2025447 AMAQI
31st Jul 2025458 AMAQI
31st Jul 2025449 AMAQI
31st Jul 20254510 AMAQI
31st Jul 20254611 AMAQI
31st Jul 20254612 PMAQI
31st Jul 2025451 PMAQI
31st Jul 2025452 PMAQI
31st Jul 2025423 PMAQI
31st Jul 2025384 PMAQI
31st Jul 2025365 PMAQI
31st Jul 2025376 PMAQI
31st Jul 2025447 PMAQI
31st Jul 2025458 PMAQI
31st Jul 2025469 PMAQI
31st Jul 20254710 PMAQI
31st Jul 20254911 PMAQI
1st Aug 20254812 AMAQI
1st Aug 2025461 AMAQI
1st Aug 2025462 AMAQI
1st Aug 2025413 AMAQI
1st Aug 2025404 AMAQI
26°C23/29°C
1st Aug 2025395 AMAQI
1st Aug 2025406 AMAQI
1st Aug 2025437 AMAQI
1st Aug 2025478 AMAQI
1st Aug 2025499 AMAQI
1st Aug 20255110 AMAQI
1st Aug 20255211 AMAQI
1st Aug 20255012 PMAQI
1st Aug 2025491 PMAQI
1st Aug 2025482 PMAQI
1st Aug 2025483 PMAQI
1st Aug 2025484 PMAQI
1st Aug 2025505 PMAQI
1st Aug 2025486 PMAQI
1st Aug 2025497 PMAQI
1st Aug 2025488 PMAQI
1st Aug 2025499 PMAQI
1st Aug 20255110 PMAQI
1st Aug 20255311 PMAQI
2nd Aug 20255312 AMAQI
2nd Aug 2025531 AMAQI
2nd Aug 2025552 AMAQI
2nd Aug 2025553 AMAQI
2nd Aug 2025554 AMAQI
23°C18/29°C
2nd Aug 2025535 AMAQI
2nd Aug 2025526 AMAQI
2nd Aug 2025527 AMAQI
2nd Aug 2025518 AMAQI
2nd Aug 2025509 AMAQI
2nd Aug 20255010 AMAQI
2nd Aug 20255011 AMAQI
2nd Aug 20254612 PMAQI
2nd Aug 2025431 PMAQI
2nd Aug 2025412 PMAQI
2nd Aug 2025413 PMAQI
2nd Aug 2025384 PMAQI
2nd Aug 2025365 PMAQI
2nd Aug 2025366 PMAQI
2nd Aug 2025477 PMAQI
2nd Aug 2025448 PMAQI
2nd Aug 2025419 PMAQI
2nd Aug 20254310 PMAQI
2nd Aug 20254611 PMAQI
3rd Aug 20254512 AMAQI
3rd Aug 2025461 AMAQI
3rd Aug 2025472 AMAQI
3rd Aug 2025463 AMAQI
3rd Aug 2025444 AMAQI
21°C14/26°C
3rd Aug 2025435 AMAQI
3rd Aug 2025456 AMAQI
3rd Aug 2025457 AMAQI
3rd Aug 2025438 AMAQI
3rd Aug 2025439 AMAQI
3rd Aug 20254310 AMAQI
3rd Aug 20254511 AMAQI
3rd Aug 20254612 PMAQI
3rd Aug 2025461 PMAQI
3rd Aug 2025462 PMAQI
3rd Aug 2025463 PMAQI
3rd Aug 2025464 PMAQI
3rd Aug 2025455 PMAQI
3rd Aug 2025456 PMAQI
3rd Aug 2025447 PMAQI
3rd Aug 2025438 PMAQI
3rd Aug 2025439 PMAQI
3rd Aug 20254210 PMAQI
3rd Aug 20254211 PMAQI
4th Aug 20254412 AMAQI
4th Aug 2025451 AMAQI
4th Aug 2025442 AMAQI
4th Aug 2025443 AMAQI
4th Aug 2025444 AMAQI
22°C13/29°C
4th Aug 2025445 AMAQI
4th Aug 2025446 AMAQI
4th Aug 2025447 AMAQI
4th Aug 2025448 AMAQI
4th Aug 2025479 AMAQI
4th Aug 20254810 AMAQI
4th Aug 20255011 AMAQI
4th Aug 20255412 PMAQI
4th Aug 2025571 PMAQI
4th Aug 2025592 PMAQI
4th Aug 2025603 PMAQI
4th Aug 2025604 PMAQI
4th Aug 2025625 PMAQI
4th Aug 2025626 PMAQI
4th Aug 2025467 PMAQI
4th Aug 2025528 PMAQI
4th Aug 2025579 PMAQI
4th Aug 20255610 PMAQI
4th Aug 20255611 PMAQI
5th Aug 20255512 AMAQI
5th Aug 2025561 AMAQI
5th Aug 2025602 AMAQI
5th Aug 2025593 AMAQI
5th Aug 2025594 AMAQI
22°C16/29°C
5th Aug 2025615 AMAQI
5th Aug 2025606 AMAQI
5th Aug 2025627 AMAQI
5th Aug 2025648 AMAQI
5th Aug 2025639 AMAQI
5th Aug 20256210 AMAQI
5th Aug 20256511 AMAQI
5th Aug 20256612 PMAQI
5th Aug 2025681 PMAQI
5th Aug 2025682 PMAQI
5th Aug 2025663 PMAQI
5th Aug 2025664 PMAQI
5th Aug 2025645 PMAQI
5th Aug 2025636 PMAQI
5th Aug 2025607 PMAQI
5th Aug 2025628 PMAQI
5th Aug 2025619 PMAQI
5th Aug 20256110 PMAQI
5th Aug 20256111 PMAQI
6th Aug 20256012 AMAQI
6th Aug 2025591 AMAQI
6th Aug 2025582 AMAQI
6th Aug 2025583 AMAQI
6th Aug 2025584 AMAQI
24°C19/31°C
6th Aug 2025585 AMAQI
6th Aug 2025576 AMAQI
6th Aug 2025597 AMAQI
6th Aug 2025608 AMAQI
6th Aug 2025609 AMAQI
6th Aug 20256110 AMAQI
6th Aug 20256411 AMAQI
6th Aug 20256612 PMAQI
6th Aug 2025671 PMAQI
6th Aug 2025662 PMAQI
6th Aug 2025663 PMAQI
6th Aug 2025644 PMAQI
6th Aug 2025645 PMAQI
6th Aug 2025616 PMAQI
6th Aug 2025617 PMAQI
6th Aug 2025568 PMAQI
6th Aug 2025509 PMAQI
6th Aug 20254910 PMAQI
6th Aug 20254611 PMAQI
7th Aug 20254812 AMAQI
7th Aug 2025481 AMAQI
7th Aug 2025432 AMAQI
7th Aug 2025403 AMAQI
7th Aug 2025374 AMAQI
26°C17/33°C
7th Aug 2025375 AMAQI
7th Aug 2025386 AMAQI
7th Aug 2025397 AMAQI
7th Aug 2025418 AMAQI
7th Aug 2025439 AMAQI
7th Aug 20255310 AMAQI
7th Aug 20255611 AMAQI
7th Aug 20255612 PMAQI
7th Aug 2025591 PMAQI
7th Aug 2025602 PMAQI
7th Aug 2025573 PMAQI
7th Aug 2025574 PMAQI
7th Aug 2025555 PMAQI
7th Aug 2025546 PMAQI
7th Aug 2025507 PMAQI
7th Aug 2025498 PMAQI
7th Aug 2025489 PMAQI
7th Aug 20254610 PMAQI
7th Aug 20254611 PMAQI
8th Aug 20254412 AMAQI
8th Aug 2025431 AMAQI
8th Aug 2025392 AMAQI
8th Aug 2025373 AMAQI
8th Aug 2025354 AMAQI
27°C21/35°C
8th Aug 2025365 AMAQI
8th Aug 2025356 AMAQI
8th Aug 2025367 AMAQI
8th Aug 2025378 AMAQI
8th Aug 2025369 AMAQI
8th Aug 20254010 AMAQI
8th Aug 20254011 AMAQI
8th Aug 20253812 PMAQI
8th Aug 2025361 PMAQI
8th Aug 2025382 PMAQI
8th Aug 2025403 PMAQI
8th Aug 2025404 PMAQI
8th Aug 2025405 PMAQI
8th Aug 2025406 PMAQI
8th Aug 2025397 PMAQI
8th Aug 2025398 PMAQI
8th Aug 2025389 PMAQI
8th Aug 20253610 PMAQI
8th Aug 20253711 PMAQI
9th Aug 20253812 AMAQI
9th Aug 2025381 AMAQI
9th Aug 2025362 AMAQI
9th Aug 2025363 AMAQI
9th Aug 2025354 AMAQI
29°C23/35°C
9th Aug 2025335 AMAQI
5 AM12 PM
8 PM
12 AM
4 AM
--°C/°C
Day time
Avg. Highest Time
5 AM - 8 PM
42AQI
16 hours / Day
480 hours / Month
Avg. Lowest Time
5 AM - 8 PM
42AQI
16 hours / Day
480 hours / Month
In the last 30 days, during the daytime, the highest AQI was between 5 AM to 8 PM (Avg. 42), while the lowest AQI was between 5 AM to 8 PM (Avg. 42).
Night time
Avg. Highest Time
12 AM - 11 PM
40AQI
8 hours / Day
240 hours / Month
Avg. Lowest Time
12 AM - 4 AM
40AQI
5 hours / Day
150 hours / Month
In the last 30 days, during the daytime, the highest AQI was between 12 AM to 11 PM (Avg. 40), while the lowest AQI was between 12 AM to 4 AM (Avg. 40).
2025 Days Vs Air Quality
Chester, Illinois, United States
2025
85%
186
15%
33
0.4%
1
Total number of days with different AQI categories in last 221 days in 2025 (144 days remaining)
Good
186 DaysModerate
33 DaysPoor
1 DaysUnhealthy
0 DaysSevere
0 DaysHazardous
0 DaysUnder WHO’s Safe Air Quality Limits: 85%
Health Risk Level:
Low
In 2025, 85% of 221 days were within WHO’s safe air quality limits. The risk of health issues is Low, but the long-term effects, especially on vulnerable individuals, remain uncertain.
Annual Air Quality Insights
Chester, Illinois, United States
AQI levels in 2025
AQI
PM2.5
PM10
CO
SO2
NO2
O3
Sun.Mon.Tue.Wed.Thu.Fri.Sat.
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
1st January 2025
22AQI
22AQI
2nd January 2025
25AQI
25AQI
3rd January 2025
24AQI
24AQI
4th January 2025
20AQI
20AQI
5th January 2025
20AQI
20AQI
6th January 2025
20AQI
20AQI
7th January 2025
24AQI
24AQI
8th January 2025
42AQI
42AQI
9th January 2025
54AQI
54AQI
10th January 2025
54AQI
54AQI
11th January 2025
35AQI
35AQI
12th January 2025
31AQI
31AQI
13th January 2025
23AQI
23AQI
14th January 2025
26AQI
26AQI
15th January 2025
33AQI
33AQI
16th January 2025
30AQI
30AQI
17th January 2025
27AQI
27AQI
18th January 2025
20AQI
20AQI
19th January 2025
19AQI
19AQI
20th January 2025
20AQI
20AQI
21st January 2025
22AQI
22AQI
22nd January 2025
25AQI
25AQI
23rd January 2025
26AQI
26AQI
24th January 2025
30AQI
30AQI
25th January 2025
28AQI
28AQI
26th January 2025
27AQI
27AQI
27th January 2025
22AQI
22AQI
28th January 2025
23AQI
23AQI
29th January 2025
24AQI
24AQI
30th January 2025
30AQI
30AQI
31st January 2025
21AQI
21AQI
1st February 2025
31AQI
31AQI
2nd February 2025
26AQI
26AQI
3rd February 2025
33AQI
33AQI
4th February 2025
29AQI
29AQI
5th February 2025
29AQI
29AQI
6th February 2025
26AQI
26AQI
7th February 2025
25AQI
25AQI
8th February 2025
32AQI
32AQI
9th February 2025
35AQI
35AQI
10th February 2025
33AQI
33AQI
11th February 2025
30AQI
30AQI
12th February 2025
42AQI
42AQI
13th February 2025
30AQI
30AQI
14th February 2025
26AQI
26AQI
15th February 2025
23AQI
23AQI
16th February 2025
40AQI
40AQI
17th February 2025
20AQI
20AQI
18th February 2025
22AQI
22AQI
19th February 2025
21AQI
21AQI
20th February 2025
22AQI
22AQI
21st February 2025
30AQI
30AQI
22nd February 2025
37AQI
37AQI
23rd February 2025
32AQI
32AQI
24th February 2025
28AQI
28AQI
25th February 2025
28AQI
28AQI
26th February 2025
26AQI
26AQI
27th February 2025
30AQI
30AQI
28th February 2025
28AQI
28AQI
1st March 2025
27AQI
27AQI
2nd March 2025
27AQI
27AQI
3rd March 2025
32AQI
32AQI
4th March 2025
42AQI
42AQI
5th March 2025
26AQI
26AQI
6th March 2025
27AQI
27AQI
7th March 2025
28AQI
28AQI
8th March 2025
33AQI
33AQI
9th March 2025
40AQI
40AQI
10th March 2025
46AQI
46AQI
11th March 2025
56AQI
56AQI
12th March 2025
55AQI
55AQI
13th March 2025
67AQI
67AQI
14th March 2025
50AQI
50AQI
15th March 2025
117AQI
117AQI
16th March 2025
29AQI
29AQI
17th March 2025
32AQI
32AQI
18th March 2025
25AQI
25AQI
19th March 2025
31AQI
31AQI
20th March 2025
19AQI
19AQI
21st March 2025
27AQI
27AQI
22nd March 2025
21AQI
21AQI
23rd March 2025
26AQI
26AQI
24th March 2025
19AQI
19AQI
25th March 2025
20AQI
20AQI
26th March 2025
33AQI
33AQI
27th March 2025
46AQI
46AQI
28th March 2025
45AQI
45AQI
29th March 2025
47AQI
47AQI
30th March 2025
32AQI
32AQI
31st March 2025
20AQI
20AQI
1st April 2025
28AQI
28AQI
2nd April 2025
31AQI
31AQI
3rd April 2025
25AQI
25AQI
4th April 2025
22AQI
22AQI
5th April 2025
18AQI
18AQI
6th April 2025
23AQI
23AQI
7th April 2025
26AQI
26AQI
8th April 2025
18AQI
18AQI
9th April 2025
22AQI
22AQI
10th April 2025
40AQI
40AQI
11th April 2025
39AQI
39AQI
12th April 2025
44AQI
44AQI
13th April 2025
43AQI
43AQI
14th April 2025
41AQI
41AQI
15th April 2025
23AQI
23AQI
16th April 2025
28AQI
28AQI
17th April 2025
45AQI
45AQI
18th April 2025
60AQI
60AQI
19th April 2025
40AQI
40AQI
20th April 2025
49AQI
49AQI
21st April 2025
21AQI
21AQI
22nd April 2025
26AQI
26AQI
23rd April 2025
32AQI
32AQI
24th April 2025
41AQI
41AQI
25th April 2025
40AQI
40AQI
26th April 2025
34AQI
34AQI
27th April 2025
24AQI
24AQI
28th April 2025
37AQI
37AQI
29th April 2025
41AQI
41AQI
30th April 2025
38AQI
38AQI
1st May 2025
27AQI
27AQI
2nd May 2025
27AQI
27AQI
3rd May 2025
30AQI
30AQI
4th May 2025
22AQI
22AQI
5th May 2025
19AQI
19AQI
6th May 2025
26AQI
26AQI
7th May 2025
23AQI
23AQI
8th May 2025
27AQI
27AQI
9th May 2025
25AQI
25AQI
10th May 2025
26AQI
26AQI
11th May 2025
32AQI
32AQI
12th May 2025
25AQI
25AQI
13th May 2025
22AQI
22AQI
14th May 2025
41AQI
41AQI
15th May 2025
54AQI
54AQI
16th May 2025
54AQI
54AQI
17th May 2025
27AQI
27AQI
18th May 2025
22AQI
22AQI
19th May 2025
29AQI
29AQI
20th May 2025
29AQI
29AQI
21st May 2025
16AQI
16AQI
22nd May 2025
14AQI
14AQI
23rd May 2025
17AQI
17AQI
24th May 2025
29AQI
29AQI
25th May 2025
34AQI
34AQI
26th May 2025
22AQI
22AQI
27th May 2025
21AQI
21AQI
28th May 2025
28AQI
28AQI
29th May 2025
37AQI
37AQI
30th May 2025
29AQI
29AQI
31st May 2025
41AQI
41AQI
1st June 2025
39AQI
39AQI
2nd June 2025
44AQI
44AQI
3rd June 2025
57AQI
57AQI
4th June 2025
61AQI
61AQI
5th June 2025
52AQI
52AQI
6th June 2025
47AQI
47AQI
7th June 2025
53AQI
53AQI
8th June 2025
53AQI
53AQI
9th June 2025
57AQI
57AQI
10th June 2025
61AQI
61AQI
11th June 2025
68AQI
68AQI
12th June 2025
79AQI
79AQI
13th June 2025
44AQI
44AQI
14th June 2025
38AQI
38AQI
15th June 2025
41AQI
41AQI
16th June 2025
28AQI
28AQI
17th June 2025
36AQI
36AQI
18th June 2025
34AQI
34AQI
19th June 2025
26AQI
26AQI
20th June 2025
38AQI
38AQI
21st June 2025
50AQI
50AQI
22nd June 2025
53AQI
53AQI
23rd June 2025
57AQI
57AQI
24th June 2025
55AQI
55AQI
25th June 2025
54AQI
54AQI
26th June 2025
52AQI
52AQI
27th June 2025
42AQI
42AQI
28th June 2025
28AQI
28AQI
29th June 2025
27AQI
27AQI
30th June 2025
29AQI
29AQI
1st July 2025
30AQI
30AQI
2nd July 2025
38AQI
38AQI
3rd July 2025
53AQI
53AQI
4th July 2025
60AQI
60AQI
5th July 2025
70AQI
70AQI
6th July 2025
59AQI
59AQI
7th July 2025
40AQI
40AQI
8th July 2025
39AQI
39AQI
9th July 2025
34AQI
34AQI
10th July 2025
42AQI
42AQI
11th July 2025
43AQI
43AQI
12th July 2025
40AQI
40AQI
13th July 2025
33AQI
33AQI
14th July 2025
33AQI
33AQI
15th July 2025
34AQI
34AQI
16th July 2025
34AQI
34AQI
17th July 2025
37AQI
37AQI
18th July 2025
31AQI
31AQI
19th July 2025
43AQI
43AQI
20th July 2025
52AQI
52AQI
21st July 2025
34AQI
34AQI
22nd July 2025
41AQI
41AQI
23rd July 2025
50AQI
50AQI
24th July 2025
54AQI
54AQI
25th July 2025
54AQI
54AQI
26th July 2025
44AQI
44AQI
27th July 2025
30AQI
30AQI
28th July 2025
36AQI
36AQI
29th July 2025
45AQI
45AQI
30th July 2025
46AQI
46AQI
31st July 2025
38AQI
38AQI
1st August 2025
89AQI
89AQI
2nd August 2025
78AQI
78AQI
3rd August 2025
51AQI
51AQI
4th August 2025
38AQI
38AQI
5th August 2025
40AQI
40AQI
6th August 2025
45AQI
45AQI
7th August 2025
50AQI
50AQI
8th August 2025
52AQI
52AQI
27AQI
29AQI
37AQI
33AQI
28AQI
47AQI
42AQI
55AQI
No. of days
Jan.Feb.Mar.Apr.MayJun.Jul.Aug.Sep.Oct.Nov.Dec.Total Days
202536AQI
29
2
28
27
3
1
29
1
29
2
16
14
24
7
4
4
186
33
1
Highest AQI recorded in
August55AQI
Lowest AQI recorded in
January27AQI
202431AQI
30
1
26
3
31
30
31
28
1
29
2
29
2
30
27
4
30
31
352
13
Highest AQI recorded in
October37AQI
Lowest AQI recorded in
January24AQI
202338AQI
27
4
28
30
1
27
3
25
6
8
22
28
3
23
8
26
4
27
4
29
31
309
55
Highest AQI recorded in
June59AQI
Lowest AQI recorded in
December25AQI
202236AQI
27
4
21
30
1
17
27
4
25
5
19
4
2
28
1
27
4
26
4
23
8
272
35
Highest AQI recorded in
June44AQI
Lowest AQI recorded in
September32AQI
202138AQI
28
2
17
5
24
4
27
3
29
2
23
5
16
15
24
7
21
4
29
2
17
3
27
4
282
56
Highest AQI recorded in
July50AQI
Lowest AQI recorded in
October30AQI
202040AQI
10
3
17
3
18
24
4
2
27
4
30
1
27
2
27
2
1
25
3
21
8
226
30
3
Highest AQI recorded in
June48AQI
Lowest AQI recorded in
May32AQI
Most & Least Polluted Years Over the Last 6 Years
Most Polluted Year Recorded
2020(Avg.)
40AQILeast Polluted Year Recorded
2024(Avg.)
31AQIChester's annual 2025 AQI (36) shows an average percentage change of -1.5% (improved AQI) compared to previous years: 2020 (40), 2021 (38), 2022 (36), 2023 (38), 2024 (31).
