Decatur, 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
Decatur, Illinois, United States
2021
2022
2023
2024
2025
AQI
.
Days
AQI Trends: Highest and Lowest
Highest AQI recorded on
1st Aug 2025
112AQILowest AQI recorded on
10th Aug 2024
21AQISame Day Analysis (6th August ):
On this day, AQI across the 5 years varied significantly: 2025 ranks 2nd highest AQI at 57 of Moderate air quality, showing improvement over 2021 on the same day.
Download 2024 Annual Data
World Air Quality Report
Day & Night AQI Trend: 6th Aug - 7th Aug 2025
Decatur, Illinois, United States
AQI
Day
Night
.
5 AM6th Aug 2025
8 PM
4 AM7th Aug 2025
Day time
Avg. Highest Time
8AM6th Aug
43AQI
Avg. Lowest Time
6PM6th Aug
30AQI
Night time
Avg. Highest Time
9PM6th Aug
39AQI
Avg. Lowest Time
3AM7th Aug
32AQI
In the last 24 hours,
Decatur's AQI reached its highest point of 43 at 8 AM during the Day, while the lowest point, 30, was recorded at 6 PM during the Day between 6th Aug and 7th Aug 2025.
Day & Night AQI Trend : Jul - Aug 2025
Decatur, Illinois, United States
JulAug
08th - 09th09th - 10th10th - 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
Day
Night
8th Jul 2025575 AMAQI
8th Jul 2025596 AMAQI
8th Jul 2025617 AMAQI
8th Jul 2025608 AMAQI
8th Jul 2025609 AMAQI
8th Jul 20256210 AMAQI
8th Jul 20256211 AMAQI
8th Jul 20256012 PMAQI
8th Jul 2025621 PMAQI
8th Jul 2025612 PMAQI
8th Jul 2025613 PMAQI
8th Jul 2025614 PMAQI
8th Jul 2025615 PMAQI
8th Jul 2025586 PMAQI
8th Jul 2025587 PMAQI
8th Jul 2025588 PMAQI
8th Jul 2025569 PMAQI
8th Jul 20255510 PMAQI
8th Jul 20255511 PMAQI
9th Jul 20255412 AMAQI
9th Jul 2025521 AMAQI
9th Jul 2025362 AMAQI
9th Jul 2025373 AMAQI
9th Jul 2025374 AMAQI
24°C17/33°C
9th Jul 2025365 AMAQI
9th Jul 2025396 AMAQI
9th Jul 2025407 AMAQI
9th Jul 2025418 AMAQI
9th Jul 2025459 AMAQI
9th Jul 20254010 AMAQI
9th Jul 20254011 AMAQI
9th Jul 20254212 PMAQI
9th Jul 2025441 PMAQI
9th Jul 2025452 PMAQI
9th Jul 2025473 PMAQI
9th Jul 2025504 PMAQI
9th Jul 2025475 PMAQI
9th Jul 2025466 PMAQI
9th Jul 2025447 PMAQI
9th Jul 2025448 PMAQI
9th Jul 2025449 PMAQI
9th Jul 20254310 PMAQI
9th Jul 20254311 PMAQI
10th Jul 20254112 AMAQI
10th Jul 2025381 AMAQI
10th Jul 2025322 AMAQI
10th Jul 2025343 AMAQI
10th Jul 2025324 AMAQI
25°C18/32°C
10th Jul 2025315 AMAQI
10th Jul 2025326 AMAQI
10th Jul 2025347 AMAQI
10th Jul 2025318 AMAQI
10th Jul 2025319 AMAQI
10th Jul 20253210 AMAQI
10th Jul 20253311 AMAQI
10th Jul 20253412 PMAQI
10th Jul 2025401 PMAQI
10th Jul 2025382 PMAQI
10th Jul 2025383 PMAQI
10th Jul 2025364 PMAQI
10th Jul 2025365 PMAQI
10th Jul 2025366 PMAQI
10th Jul 2025357 PMAQI
10th Jul 2025368 PMAQI
10th Jul 2025369 PMAQI
10th Jul 20253710 PMAQI
10th Jul 20253711 PMAQI
11th Jul 20253712 AMAQI
11th Jul 2025371 AMAQI
11th Jul 2025362 AMAQI
11th Jul 2025373 AMAQI
11th Jul 2025354 AMAQI
26°C19/33°C
11th Jul 2025365 AMAQI
11th Jul 2025356 AMAQI
11th Jul 2025357 AMAQI
11th Jul 2025368 AMAQI
11th Jul 2025379 AMAQI
11th Jul 20253810 AMAQI
11th Jul 20253811 AMAQI
11th Jul 20254312 PMAQI
11th Jul 2025421 PMAQI
11th Jul 2025422 PMAQI
11th Jul 2025423 PMAQI
11th Jul 2025424 PMAQI
11th Jul 2025435 PMAQI
11th Jul 2025436 PMAQI
11th Jul 2025407 PMAQI
11th Jul 2025418 PMAQI
11th Jul 2025429 PMAQI
11th Jul 20254110 PMAQI
11th Jul 20254211 PMAQI
12th Jul 20254212 AMAQI
12th Jul 2025411 AMAQI
12th Jul 2025362 AMAQI
12th Jul 2025343 AMAQI
12th Jul 2025364 AMAQI
27°C21/35°C
12th Jul 2025365 AMAQI
12th Jul 2025366 AMAQI
12th Jul 2025367 AMAQI
12th Jul 2025368 AMAQI
12th Jul 2025329 AMAQI
12th Jul 20253510 AMAQI
12th Jul 20253711 AMAQI
12th Jul 20253712 PMAQI
12th Jul 2025411 PMAQI
12th Jul 2025402 PMAQI
12th Jul 2025403 PMAQI
12th Jul 2025414 PMAQI
12th Jul 2025415 PMAQI
12th Jul 2025426 PMAQI
12th Jul 2025397 PMAQI
12th Jul 2025398 PMAQI
12th Jul 2025419 PMAQI
12th Jul 20254210 PMAQI
12th Jul 20254311 PMAQI
13th Jul 20254312 AMAQI
13th Jul 2025431 AMAQI
13th Jul 2025432 AMAQI
13th Jul 2025373 AMAQI
13th Jul 2025414 AMAQI
25°C21/29°C
13th Jul 2025425 AMAQI
13th Jul 2025426 AMAQI
13th Jul 2025447 AMAQI
13th Jul 2025448 AMAQI
13th Jul 2025489 AMAQI
13th Jul 20254910 AMAQI
13th Jul 20255111 AMAQI
13th Jul 20255012 PMAQI
13th Jul 2025521 PMAQI
13th Jul 2025512 PMAQI
13th Jul 2025473 PMAQI
13th Jul 2025454 PMAQI
13th Jul 2025435 PMAQI
13th Jul 2025436 PMAQI
13th Jul 2025437 PMAQI
13th Jul 2025438 PMAQI
13th Jul 2025419 PMAQI
13th Jul 20254010 PMAQI
13th Jul 20254211 PMAQI
14th Jul 20254112 AMAQI
14th Jul 2025401 AMAQI
14th Jul 2025352 AMAQI
14th Jul 2025333 AMAQI
14th Jul 2025314 AMAQI
24°C21/31°C
14th Jul 2025275 AMAQI
14th Jul 2025286 AMAQI
14th Jul 2025277 AMAQI
14th Jul 2025278 AMAQI
14th Jul 2025289 AMAQI
14th Jul 20253410 AMAQI
14th Jul 20254011 AMAQI
14th Jul 20254012 PMAQI
14th Jul 2025411 PMAQI
14th Jul 2025422 PMAQI
14th Jul 2025413 PMAQI
14th Jul 2025394 PMAQI
14th Jul 2025375 PMAQI
14th Jul 2025386 PMAQI
14th Jul 2025367 PMAQI
14th Jul 2025358 PMAQI
14th Jul 2025369 PMAQI
14th Jul 20253410 PMAQI
14th Jul 20253511 PMAQI
15th Jul 20253512 AMAQI
15th Jul 2025371 AMAQI
15th Jul 2025352 AMAQI
15th Jul 2025323 AMAQI
15th Jul 2025364 AMAQI
26°C21/32°C
15th Jul 2025345 AMAQI
15th Jul 2025346 AMAQI
15th Jul 2025377 AMAQI
15th Jul 2025398 AMAQI
15th Jul 2025429 AMAQI
15th Jul 20253910 AMAQI
15th Jul 20254311 AMAQI
15th Jul 20254212 PMAQI
15th Jul 2025411 PMAQI
15th Jul 2025402 PMAQI
15th Jul 2025413 PMAQI
15th Jul 2025404 PMAQI
15th Jul 2025405 PMAQI
15th Jul 2025406 PMAQI
15th Jul 2025387 PMAQI
15th Jul 2025398 PMAQI
15th Jul 2025389 PMAQI
15th Jul 20253810 PMAQI
15th Jul 20253711 PMAQI
16th Jul 20253712 AMAQI
16th Jul 2025381 AMAQI
16th Jul 2025342 AMAQI
16th Jul 2025313 AMAQI
16th Jul 2025354 AMAQI
25°C20/30°C
16th Jul 2025325 AMAQI
16th Jul 2025356 AMAQI
16th Jul 2025367 AMAQI
16th Jul 2025408 AMAQI
16th Jul 2025389 AMAQI
16th Jul 20253610 AMAQI
16th Jul 20254111 AMAQI
16th Jul 20254212 PMAQI
16th Jul 2025421 PMAQI
16th Jul 2025402 PMAQI
16th Jul 2025413 PMAQI
16th Jul 2025424 PMAQI
16th Jul 2025395 PMAQI
16th Jul 2025376 PMAQI
16th Jul 2025377 PMAQI
16th Jul 2025368 PMAQI
16th Jul 2025379 PMAQI
16th Jul 20253710 PMAQI
16th Jul 20253611 PMAQI
17th Jul 20253612 AMAQI
17th Jul 2025371 AMAQI
17th Jul 2025382 AMAQI
17th Jul 2025343 AMAQI
17th Jul 2025344 AMAQI
26°C20/35°C
17th Jul 2025355 AMAQI
17th Jul 2025386 AMAQI
17th Jul 2025347 AMAQI
17th Jul 2025328 AMAQI
17th Jul 2025309 AMAQI
17th Jul 20253110 AMAQI
17th Jul 20253111 AMAQI
17th Jul 20253312 PMAQI
17th Jul 2025351 PMAQI
17th Jul 2025332 PMAQI
17th Jul 2025343 PMAQI
17th Jul 2025344 PMAQI
17th Jul 2025335 PMAQI
17th Jul 2025326 PMAQI
17th Jul 2025337 PMAQI
17th Jul 2025328 PMAQI
17th Jul 2025309 PMAQI
17th Jul 20253010 PMAQI
17th Jul 20253011 PMAQI
18th Jul 20253212 AMAQI
18th Jul 2025311 AMAQI
18th Jul 2025292 AMAQI
18th Jul 2025253 AMAQI
18th Jul 2025264 AMAQI
26°C21/30°C
18th Jul 2025245 AMAQI
18th Jul 2025246 AMAQI
18th Jul 2025257 AMAQI
18th Jul 2025258 AMAQI
18th Jul 2025239 AMAQI
18th Jul 20252310 AMAQI
18th Jul 20252111 AMAQI
18th Jul 20252312 PMAQI
18th Jul 2025261 PMAQI
18th Jul 2025292 PMAQI
18th Jul 2025293 PMAQI
18th Jul 2025314 PMAQI
18th Jul 2025315 PMAQI
18th Jul 2025286 PMAQI
18th Jul 2025287 PMAQI
18th Jul 2025278 PMAQI
18th Jul 2025299 PMAQI
18th Jul 20252810 PMAQI
18th Jul 20252911 PMAQI
19th Jul 20252912 AMAQI
19th Jul 2025291 AMAQI
19th Jul 2025342 AMAQI
19th Jul 2025343 AMAQI
19th Jul 2025384 AMAQI
24°C19/29°C
19th Jul 2025365 AMAQI
19th Jul 2025376 AMAQI
19th Jul 2025357 AMAQI
19th Jul 2025358 AMAQI
19th Jul 2025339 AMAQI
19th Jul 20253510 AMAQI
19th Jul 20253311 AMAQI
19th Jul 20253312 PMAQI
19th Jul 2025341 PMAQI
19th Jul 2025322 PMAQI
19th Jul 2025343 PMAQI
19th Jul 2025334 PMAQI
19th Jul 2025335 PMAQI
19th Jul 2025316 PMAQI
19th Jul 2025357 PMAQI
19th Jul 2025338 PMAQI
19th Jul 2025359 PMAQI
19th Jul 20253710 PMAQI
19th Jul 20253611 PMAQI
20th Jul 20253712 AMAQI
20th Jul 2025381 AMAQI
20th Jul 2025392 AMAQI
20th Jul 2025383 AMAQI
20th Jul 2025414 AMAQI
25°C21/30°C
20th Jul 2025385 AMAQI
20th Jul 2025386 AMAQI
20th Jul 2025397 AMAQI
20th Jul 2025418 AMAQI
20th Jul 2025439 AMAQI
20th Jul 20253610 AMAQI
20th Jul 20253511 AMAQI
20th Jul 20253512 PMAQI
20th Jul 2025351 PMAQI
20th Jul 2025362 PMAQI
20th Jul 2025373 PMAQI
20th Jul 2025394 PMAQI
20th Jul 2025395 PMAQI
20th Jul 2025366 PMAQI
20th Jul 2025377 PMAQI
20th Jul 2025388 PMAQI
20th Jul 2025379 PMAQI
20th Jul 20253710 PMAQI
20th Jul 20253711 PMAQI
21st Jul 20253812 AMAQI
21st Jul 2025401 AMAQI
21st Jul 2025342 AMAQI
21st Jul 2025343 AMAQI
21st Jul 2025294 AMAQI
26°C22/31°C
21st Jul 2025355 AMAQI
21st Jul 2025346 AMAQI
21st Jul 2025357 AMAQI
21st Jul 2025378 AMAQI
21st Jul 2025369 AMAQI
21st Jul 20253810 AMAQI
21st Jul 20253611 AMAQI
21st Jul 20253612 PMAQI
21st Jul 2025401 PMAQI
21st Jul 2025412 PMAQI
21st Jul 2025423 PMAQI
21st Jul 2025424 PMAQI
21st Jul 2025415 PMAQI
21st Jul 2025386 PMAQI
21st Jul 2025387 PMAQI
21st Jul 2025388 PMAQI
21st Jul 2025419 PMAQI
21st Jul 20254110 PMAQI
21st Jul 20254111 PMAQI
22nd Jul 20254312 AMAQI
22nd Jul 2025421 AMAQI
22nd Jul 2025422 AMAQI
22nd Jul 2025383 AMAQI
22nd Jul 2025404 AMAQI
24°C23/27°C
22nd Jul 2025385 AMAQI
22nd Jul 2025426 AMAQI
22nd Jul 2025397 AMAQI
22nd Jul 2025428 AMAQI
22nd Jul 2025409 AMAQI
22nd Jul 20254210 AMAQI
22nd Jul 20254911 AMAQI
22nd Jul 20254912 PMAQI
22nd Jul 2025481 PMAQI
22nd Jul 2025482 PMAQI
22nd Jul 2025483 PMAQI
22nd Jul 2025474 PMAQI
22nd Jul 2025475 PMAQI
22nd Jul 2025456 PMAQI
22nd Jul 2025457 PMAQI
22nd Jul 2025458 PMAQI
22nd Jul 2025479 PMAQI
22nd Jul 20254710 PMAQI
22nd Jul 20254611 PMAQI
23rd Jul 20254612 AMAQI
23rd Jul 2025451 AMAQI
23rd Jul 2025402 AMAQI
23rd Jul 2025403 AMAQI
23rd Jul 2025424 AMAQI
26°C21/33°C
23rd Jul 2025435 AMAQI
23rd Jul 2025456 AMAQI
23rd Jul 2025447 AMAQI
23rd Jul 2025448 AMAQI
23rd Jul 2025459 AMAQI
23rd Jul 20254410 AMAQI
23rd Jul 20254911 AMAQI
23rd Jul 20254812 PMAQI
23rd Jul 2025501 PMAQI
23rd Jul 2025502 PMAQI
23rd Jul 2025493 PMAQI
23rd Jul 2025494 PMAQI
23rd Jul 2025495 PMAQI
23rd Jul 2025486 PMAQI
23rd Jul 2025487 PMAQI
23rd Jul 2025488 PMAQI
23rd Jul 2025499 PMAQI
23rd Jul 20254910 PMAQI
23rd Jul 20254811 PMAQI
24th Jul 20254812 AMAQI
24th Jul 2025481 AMAQI
24th Jul 2025482 AMAQI
24th Jul 2025483 AMAQI
24th Jul 2025524 AMAQI
27°C23/33°C
24th Jul 2025525 AMAQI
24th Jul 2025526 AMAQI
24th Jul 2025537 AMAQI
24th Jul 2025508 AMAQI
24th Jul 2025499 AMAQI
24th Jul 20255410 AMAQI
24th Jul 20255411 AMAQI
24th Jul 20255212 PMAQI
24th Jul 2025501 PMAQI
24th Jul 2025502 PMAQI
24th Jul 2025513 PMAQI
24th Jul 2025504 PMAQI
24th Jul 2025495 PMAQI
24th Jul 2025486 PMAQI
24th Jul 2025517 PMAQI
24th Jul 2025528 PMAQI
24th Jul 2025499 PMAQI
24th Jul 20255010 PMAQI
24th Jul 20254911 PMAQI
25th Jul 20254912 AMAQI
25th Jul 2025491 AMAQI
25th Jul 2025452 AMAQI
25th Jul 2025413 AMAQI
25th Jul 2025404 AMAQI
28°C23/33°C
25th Jul 2025345 AMAQI
25th Jul 2025326 AMAQI
25th Jul 2025357 AMAQI
25th Jul 2025368 AMAQI
25th Jul 2025359 AMAQI
25th Jul 20253510 AMAQI
25th Jul 20253111 AMAQI
25th Jul 20253112 PMAQI
25th Jul 2025301 PMAQI
25th Jul 2025342 PMAQI
25th Jul 2025383 PMAQI
25th Jul 2025374 PMAQI
25th Jul 2025365 PMAQI
25th Jul 2025356 PMAQI
25th Jul 2025397 PMAQI
25th Jul 2025388 PMAQI
25th Jul 2025379 PMAQI
25th Jul 20253710 PMAQI
25th Jul 20253711 PMAQI
26th Jul 20253812 AMAQI
26th Jul 2025361 AMAQI
26th Jul 2025282 AMAQI
26th Jul 2025253 AMAQI
26th Jul 2025304 AMAQI
27°C23/33°C
26th Jul 2025315 AMAQI
26th Jul 2025316 AMAQI
26th Jul 2025327 AMAQI
26th Jul 2025318 AMAQI
26th Jul 2025329 AMAQI
26th Jul 20253110 AMAQI
26th Jul 20253111 AMAQI
26th Jul 20253012 PMAQI
26th Jul 2025311 PMAQI
26th Jul 2025322 PMAQI
26th Jul 2025313 PMAQI
26th Jul 2025314 PMAQI
26th Jul 2025325 PMAQI
26th Jul 2025316 PMAQI
26th Jul 2025307 PMAQI
26th Jul 2025328 PMAQI
26th Jul 2025319 PMAQI
26th Jul 20253110 PMAQI
26th Jul 20253211 PMAQI
27th Jul 20253212 AMAQI
27th Jul 2025291 AMAQI
27th Jul 2025222 AMAQI
27th Jul 2025213 AMAQI
27th Jul 2025204 AMAQI
28°C24/32°C
27th Jul 2025195 AMAQI
27th Jul 2025196 AMAQI
27th Jul 2025217 AMAQI
27th Jul 2025228 AMAQI
27th Jul 2025209 AMAQI
27th Jul 20252010 AMAQI
27th Jul 20252111 AMAQI
27th Jul 20252312 PMAQI
27th Jul 2025251 PMAQI
27th Jul 2025272 PMAQI
27th Jul 2025263 PMAQI
27th Jul 2025264 PMAQI
27th Jul 2025275 PMAQI
27th Jul 2025266 PMAQI
27th Jul 2025247 PMAQI
27th Jul 2025268 PMAQI
27th Jul 2025299 PMAQI
27th Jul 20252910 PMAQI
27th Jul 20252911 PMAQI
28th Jul 20252812 AMAQI
28th Jul 2025271 AMAQI
28th Jul 2025302 AMAQI
28th Jul 2025293 AMAQI
28th Jul 2025324 AMAQI
27°C23/33°C
28th Jul 2025325 AMAQI
28th Jul 2025306 AMAQI
28th Jul 2025317 AMAQI
28th Jul 2025298 AMAQI
28th Jul 2025279 AMAQI
28th Jul 20253010 AMAQI
28th Jul 20253111 AMAQI
28th Jul 20253212 PMAQI
28th Jul 2025341 PMAQI
28th Jul 2025342 PMAQI
28th Jul 2025343 PMAQI
28th Jul 2025344 PMAQI
28th Jul 2025345 PMAQI
28th Jul 2025346 PMAQI
28th Jul 2025327 PMAQI
28th Jul 2025328 PMAQI
28th Jul 2025349 PMAQI
28th Jul 20253510 PMAQI
28th Jul 20253411 PMAQI
29th Jul 20253212 AMAQI
29th Jul 2025321 AMAQI
29th Jul 2025302 AMAQI
29th Jul 2025273 AMAQI
29th Jul 2025324 AMAQI
29°C24/35°C
29th Jul 2025305 AMAQI
29th Jul 2025316 AMAQI
29th Jul 2025317 AMAQI
29th Jul 2025318 AMAQI
29th Jul 2025309 AMAQI
29th Jul 20253310 AMAQI
29th Jul 20253211 AMAQI
29th Jul 20253612 PMAQI
29th Jul 2025361 PMAQI
29th Jul 2025382 PMAQI
29th Jul 2025373 PMAQI
29th Jul 2025384 PMAQI
29th Jul 2025385 PMAQI
29th Jul 2025376 PMAQI
29th Jul 2025347 PMAQI
29th Jul 2025338 PMAQI
29th Jul 2025389 PMAQI
29th Jul 20253810 PMAQI
29th Jul 20253811 PMAQI
30th Jul 20253812 AMAQI
30th Jul 2025381 AMAQI
30th Jul 2025392 AMAQI
30th Jul 2025363 AMAQI
30th Jul 2025374 AMAQI
28°C20/35°C
30th Jul 2025385 AMAQI
30th Jul 2025386 AMAQI
30th Jul 2025397 AMAQI
30th Jul 2025408 AMAQI
30th Jul 2025409 AMAQI
30th Jul 20254310 AMAQI
30th Jul 20254411 AMAQI
30th Jul 20254412 PMAQI
30th Jul 2025431 PMAQI
30th Jul 2025452 PMAQI
30th Jul 2025453 PMAQI
30th Jul 2025454 PMAQI
30th Jul 2025455 PMAQI
30th Jul 2025456 PMAQI
30th Jul 2025457 PMAQI
30th Jul 2025458 PMAQI
30th Jul 2025409 PMAQI
30th Jul 20254110 PMAQI
30th Jul 20254011 PMAQI
31st Jul 20253912 AMAQI
31st Jul 2025371 AMAQI
31st Jul 2025332 AMAQI
31st Jul 2025323 AMAQI
31st Jul 2025334 AMAQI
27°C22/33°C
31st Jul 2025315 AMAQI
31st Jul 2025366 AMAQI
31st Jul 2025417 AMAQI
31st Jul 2025438 AMAQI
31st Jul 2025479 AMAQI
31st Jul 20254910 AMAQI
31st Jul 20255111 AMAQI
31st Jul 20255312 PMAQI
31st Jul 2025531 PMAQI
31st Jul 2025562 PMAQI
31st Jul 2025573 PMAQI
31st Jul 2025554 PMAQI
31st Jul 2025565 PMAQI
31st Jul 2025566 PMAQI
31st Jul 2025427 PMAQI
31st Jul 2025498 PMAQI
31st Jul 2025569 PMAQI
31st Jul 20256810 PMAQI
31st Jul 20257011 PMAQI
1st Aug 20257412 AMAQI
1st Aug 2025701 AMAQI
1st Aug 2025762 AMAQI
1st Aug 2025673 AMAQI
1st Aug 2025684 AMAQI
22°C19/26°C
1st Aug 2025665 AMAQI
1st Aug 2025726 AMAQI
1st Aug 2025707 AMAQI
1st Aug 2025728 AMAQI
1st Aug 2025749 AMAQI
1st Aug 20256710 AMAQI
1st Aug 20257011 AMAQI
1st Aug 20257412 PMAQI
1st Aug 2025741 PMAQI
1st Aug 2025742 PMAQI
1st Aug 2025723 PMAQI
1st Aug 2025714 PMAQI
1st Aug 2025715 PMAQI
1st Aug 2025696 PMAQI
1st Aug 2025767 PMAQI
1st Aug 2025728 PMAQI
1st Aug 2025679 PMAQI
1st Aug 20256910 PMAQI
1st Aug 20256411 PMAQI
2nd Aug 20256512 AMAQI
2nd Aug 2025681 AMAQI
2nd Aug 2025662 AMAQI
2nd Aug 2025663 AMAQI
2nd Aug 2025694 AMAQI
20°C13/28°C
2nd Aug 2025675 AMAQI
2nd Aug 2025706 AMAQI
2nd Aug 2025717 AMAQI
2nd Aug 2025718 AMAQI
2nd Aug 2025699 AMAQI
2nd Aug 20256610 AMAQI
2nd Aug 20256411 AMAQI
2nd Aug 20255712 PMAQI
2nd Aug 2025541 PMAQI
2nd Aug 2025532 PMAQI
2nd Aug 2025533 PMAQI
2nd Aug 2025534 PMAQI
2nd Aug 2025525 PMAQI
2nd Aug 2025496 PMAQI
2nd Aug 2025637 PMAQI
2nd Aug 2025578 PMAQI
2nd Aug 2025489 PMAQI
2nd Aug 20254610 PMAQI
2nd Aug 20254611 PMAQI
3rd Aug 20254512 AMAQI
3rd Aug 2025451 AMAQI
3rd Aug 2025452 AMAQI
3rd Aug 2025463 AMAQI
3rd Aug 2025444 AMAQI
19°C12/27°C
3rd Aug 2025425 AMAQI
3rd Aug 2025416 AMAQI
3rd Aug 2025387 AMAQI
3rd Aug 2025418 AMAQI
3rd Aug 2025429 AMAQI
3rd Aug 20253910 AMAQI
3rd Aug 20253911 AMAQI
3rd Aug 20253612 PMAQI
3rd Aug 2025331 PMAQI
3rd Aug 2025312 PMAQI
3rd Aug 2025303 PMAQI
3rd Aug 2025324 PMAQI
3rd Aug 2025335 PMAQI
3rd Aug 2025326 PMAQI
3rd Aug 2025417 PMAQI
3rd Aug 2025388 PMAQI
3rd Aug 2025359 PMAQI
3rd Aug 20253810 PMAQI
3rd Aug 20253711 PMAQI
4th Aug 20254012 AMAQI
4th Aug 2025401 AMAQI
4th Aug 2025392 AMAQI
4th Aug 2025433 AMAQI
4th Aug 2025404 AMAQI
20°C12/27°C
4th Aug 2025415 AMAQI
4th Aug 2025386 AMAQI
4th Aug 2025387 AMAQI
4th Aug 2025408 AMAQI
4th Aug 2025399 AMAQI
4th Aug 20253810 AMAQI
4th Aug 20253711 AMAQI
4th Aug 20253712 PMAQI
4th Aug 2025381 PMAQI
4th Aug 2025372 PMAQI
4th Aug 2025343 PMAQI
4th Aug 2025334 PMAQI
4th Aug 2025345 PMAQI
4th Aug 2025356 PMAQI
4th Aug 2025377 PMAQI
4th Aug 2025368 PMAQI
4th Aug 2025369 PMAQI
4th Aug 20253610 PMAQI
4th Aug 20253711 PMAQI
5th Aug 20253812 AMAQI
5th Aug 2025351 AMAQI
5th Aug 2025372 AMAQI
5th Aug 2025373 AMAQI
5th Aug 2025374 AMAQI
21°C14/28°C
5th Aug 2025365 AMAQI
5th Aug 2025336 AMAQI
5th Aug 2025327 AMAQI
5th Aug 2025348 AMAQI
5th Aug 2025379 AMAQI
5th Aug 20253810 AMAQI
5th Aug 20253711 AMAQI
5th Aug 20253812 PMAQI
5th Aug 2025351 PMAQI
5th Aug 2025342 PMAQI
5th Aug 2025373 PMAQI
5th Aug 2025374 PMAQI
5th Aug 2025385 PMAQI
5th Aug 2025366 PMAQI
5th Aug 2025357 PMAQI
5th Aug 2025368 PMAQI
5th Aug 2025399 PMAQI
5th Aug 20253910 PMAQI
5th Aug 20254011 PMAQI
6th Aug 20254012 AMAQI
6th Aug 2025381 AMAQI
6th Aug 2025392 AMAQI
6th Aug 2025403 AMAQI
6th Aug 2025414 AMAQI
22°C16/29°C
6th Aug 2025405 AMAQI
6th Aug 2025416 AMAQI
6th Aug 2025417 AMAQI
6th Aug 2025438 AMAQI
6th Aug 2025419 AMAQI
6th Aug 20253810 AMAQI
6th Aug 20253811 AMAQI
6th Aug 20253712 PMAQI
6th Aug 2025371 PMAQI
6th Aug 2025352 PMAQI
6th Aug 2025333 PMAQI
6th Aug 2025344 PMAQI
6th Aug 2025355 PMAQI
6th Aug 2025306 PMAQI
6th Aug 2025367 PMAQI
6th Aug 2025368 PMAQI
6th Aug 2025399 PMAQI
6th Aug 20253510 PMAQI
6th Aug 20253811 PMAQI
7th Aug 20253812 AMAQI
7th Aug 2025381 AMAQI
7th Aug 2025332 AMAQI
7th Aug 2025323 AMAQI
7th Aug 2025344 AMAQI
24°C15/32°C
7th Aug 2025305 AMAQI
5 AM7th Aug 2025326 AMAQI
7th Aug 2025347 AMAQI
7th Aug 2025368 AMAQI
7th Aug 2025379 AMAQI
7th Aug 20253810 AMAQI
7th Aug 20253811 AMAQI
12 PM
8 PM
12 AM
4 AM
--°C/°C
Day time
Avg. Highest Time
5 AM - 8 PM
41AQI
16 hours / Day
480 hours / Month
Avg. Lowest Time
5 AM - 8 PM
41AQI
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. 41), while the lowest AQI was between 5 AM to 8 PM (Avg. 41).
Night time
Avg. Highest Time
12 AM - 11 PM
40AQI
8 hours / Day
240 hours / Month
Avg. Lowest Time
2 AM - 4 AM
39AQI
3 hours / Day
90 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 2 AM to 4 AM (Avg. 39).
2025 Days Vs Air Quality
Decatur, Illinois, United States
2025
86%
187
14%
30
0.4%
1
Total number of days with different AQI categories in last 219 days in 2025 (146 days remaining)
Good
187 DaysModerate
30 DaysPoor
1 DaysUnhealthy
0 DaysSevere
0 DaysHazardous
0 DaysUnder WHO’s Safe Air Quality Limits: 86%
Health Risk Level:
Low
In 2025, 86% of 219 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
Decatur, 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
23AQI
23AQI
2nd January 2025
25AQI
25AQI
3rd January 2025
22AQI
22AQI
4th January 2025
20AQI
20AQI
5th January 2025
21AQI
21AQI
6th January 2025
20AQI
20AQI
7th January 2025
24AQI
24AQI
8th January 2025
42AQI
42AQI
9th January 2025
55AQI
55AQI
10th January 2025
62AQI
62AQI
11th January 2025
40AQI
40AQI
12th January 2025
38AQI
38AQI
13th January 2025
24AQI
24AQI
14th January 2025
28AQI
28AQI
15th January 2025
43AQI
43AQI
16th January 2025
35AQI
35AQI
17th January 2025
32AQI
32AQI
18th January 2025
22AQI
22AQI
19th January 2025
20AQI
20AQI
20th January 2025
20AQI
20AQI
21st January 2025
21AQI
21AQI
22nd January 2025
24AQI
24AQI
23rd January 2025
34AQI
34AQI
24th January 2025
34AQI
34AQI
25th January 2025
35AQI
35AQI
26th January 2025
21AQI
21AQI
27th January 2025
24AQI
24AQI
28th January 2025
26AQI
26AQI
29th January 2025
21AQI
21AQI
30th January 2025
32AQI
32AQI
31st January 2025
26AQI
26AQI
1st February 2025
25AQI
25AQI
2nd February 2025
37AQI
37AQI
3rd February 2025
38AQI
38AQI
4th February 2025
23AQI
23AQI
5th February 2025
35AQI
35AQI
6th February 2025
32AQI
32AQI
7th February 2025
22AQI
22AQI
8th February 2025
32AQI
32AQI
9th February 2025
36AQI
36AQI
10th February 2025
27AQI
27AQI
11th February 2025
35AQI
35AQI
12th February 2025
52AQI
52AQI
13th February 2025
35AQI
35AQI
14th February 2025
27AQI
27AQI
15th February 2025
36AQI
36AQI
16th February 2025
33AQI
33AQI
17th February 2025
22AQI
22AQI
18th February 2025
22AQI
22AQI
19th February 2025
22AQI
22AQI
20th February 2025
22AQI
22AQI
21st February 2025
28AQI
28AQI
22nd February 2025
47AQI
47AQI
23rd February 2025
43AQI
43AQI
24th February 2025
40AQI
40AQI
25th February 2025
35AQI
35AQI
26th February 2025
28AQI
28AQI
27th February 2025
35AQI
35AQI
28th February 2025
27AQI
27AQI
1st March 2025
26AQI
26AQI
2nd March 2025
30AQI
30AQI
3rd March 2025
33AQI
33AQI
4th March 2025
39AQI
39AQI
5th March 2025
25AQI
25AQI
6th March 2025
27AQI
27AQI
7th March 2025
26AQI
26AQI
8th March 2025
36AQI
36AQI
9th March 2025
32AQI
32AQI
10th March 2025
37AQI
37AQI
11th March 2025
39AQI
39AQI
12th March 2025
40AQI
40AQI
13th March 2025
54AQI
54AQI
14th March 2025
51AQI
51AQI
15th March 2025
100AQI
100AQI
16th March 2025
25AQI
25AQI
17th March 2025
30AQI
30AQI
18th March 2025
28AQI
28AQI
19th March 2025
32AQI
32AQI
20th March 2025
18AQI
18AQI
21st March 2025
28AQI
28AQI
22nd March 2025
22AQI
22AQI
23rd March 2025
23AQI
23AQI
24th March 2025
21AQI
21AQI
25th March 2025
21AQI
21AQI
26th March 2025
29AQI
29AQI
27th March 2025
40AQI
40AQI
28th March 2025
40AQI
40AQI
29th March 2025
43AQI
43AQI
30th March 2025
31AQI
31AQI
31st March 2025
17AQI
17AQI
1st April 2025
27AQI
27AQI
2nd April 2025
27AQI
27AQI
3rd April 2025
23AQI
23AQI
4th April 2025
34AQI
34AQI
5th April 2025
20AQI
20AQI
6th April 2025
20AQI
20AQI
7th April 2025
27AQI
27AQI
8th April 2025
18AQI
18AQI
9th April 2025
23AQI
23AQI
10th April 2025
34AQI
34AQI
11th April 2025
42AQI
42AQI
12th April 2025
40AQI
40AQI
13th April 2025
35AQI
35AQI
14th April 2025
35AQI
35AQI
15th April 2025
20AQI
20AQI
16th April 2025
28AQI
28AQI
17th April 2025
39AQI
39AQI
18th April 2025
53AQI
53AQI
19th April 2025
50AQI
50AQI
20th April 2025
39AQI
39AQI
21st April 2025
18AQI
18AQI
22nd April 2025
24AQI
24AQI
23rd April 2025
27AQI
27AQI
24th April 2025
36AQI
36AQI
25th April 2025
35AQI
35AQI
26th April 2025
23AQI
23AQI
27th April 2025
19AQI
19AQI
28th April 2025
32AQI
32AQI
29th April 2025
32AQI
32AQI
30th April 2025
25AQI
25AQI
1st May 2025
24AQI
24AQI
2nd May 2025
22AQI
22AQI
3rd May 2025
23AQI
23AQI
4th May 2025
17AQI
17AQI
5th May 2025
23AQI
23AQI
6th May 2025
27AQI
27AQI
7th May 2025
24AQI
24AQI
8th May 2025
26AQI
26AQI
9th May 2025
25AQI
25AQI
10th May 2025
32AQI
32AQI
11th May 2025
26AQI
26AQI
12th May 2025
31AQI
31AQI
13th May 2025
22AQI
22AQI
14th May 2025
28AQI
28AQI
15th May 2025
49AQI
49AQI
16th May 2025
35AQI
35AQI
17th May 2025
20AQI
20AQI
18th May 2025
18AQI
18AQI
19th May 2025
26AQI
26AQI
20th May 2025
24AQI
24AQI
21st May 2025
14AQI
14AQI
22nd May 2025
14AQI
14AQI
23rd May 2025
19AQI
19AQI
24th May 2025
24AQI
24AQI
25th May 2025
26AQI
26AQI
26th May 2025
19AQI
19AQI
27th May 2025
20AQI
20AQI
28th May 2025
27AQI
27AQI
29th May 2025
38AQI
38AQI
30th May 2025
31AQI
31AQI
31st May 2025
46AQI
46AQI
1st June 2025
31AQI
31AQI
2nd June 2025
44AQI
44AQI
3rd June 2025
57AQI
57AQI
4th June 2025
44AQI
44AQI
5th June 2025
47AQI
47AQI
6th June 2025
62AQI
62AQI
7th June 2025
67AQI
67AQI
8th June 2025
61AQI
61AQI
9th June 2025
59AQI
59AQI
10th June 2025
55AQI
55AQI
11th June 2025
64AQI
64AQI
12th June 2025
79AQI
79AQI
13th June 2025
69AQI
69AQI
14th June 2025
49AQI
49AQI
15th June 2025
43AQI
43AQI
16th June 2025
39AQI
39AQI
17th June 2025
27AQI
27AQI
18th June 2025
37AQI
37AQI
19th June 2025
23AQI
23AQI
20th June 2025
33AQI
33AQI
21st June 2025
42AQI
42AQI
22nd June 2025
46AQI
46AQI
23rd June 2025
57AQI
57AQI
24th June 2025
53AQI
53AQI
25th June 2025
51AQI
51AQI
26th June 2025
51AQI
51AQI
27th June 2025
35AQI
35AQI
28th June 2025
27AQI
27AQI
29th June 2025
32AQI
32AQI
30th June 2025
28AQI
28AQI
1st July 2025
27AQI
27AQI
2nd July 2025
42AQI
42AQI
3rd July 2025
49AQI
49AQI
4th July 2025
54AQI
54AQI
5th July 2025
65AQI
65AQI
6th July 2025
57AQI
57AQI
7th July 2025
45AQI
45AQI
8th July 2025
65AQI
65AQI
9th July 2025
40AQI
40AQI
10th July 2025
38AQI
38AQI
11th July 2025
45AQI
45AQI
12th July 2025
34AQI
34AQI
13th July 2025
39AQI
39AQI
14th July 2025
39AQI
39AQI
15th July 2025
40AQI
40AQI
16th July 2025
33AQI
33AQI
17th July 2025
27AQI
27AQI
18th July 2025
28AQI
28AQI
19th July 2025
38AQI
38AQI
20th July 2025
36AQI
36AQI
21st July 2025
29AQI
29AQI
22nd July 2025
41AQI
41AQI
23rd July 2025
57AQI
57AQI
24th July 2025
54AQI
54AQI
25th July 2025
41AQI
41AQI
26th July 2025
39AQI
39AQI
27th July 2025
26AQI
26AQI
28th July 2025
31AQI
31AQI
29th July 2025
31AQI
31AQI
30th July 2025
39AQI
39AQI
31st July 2025
49AQI
49AQI
1st August 2025
112AQI
112AQI
2nd August 2025
83AQI
83AQI
3rd August 2025
53AQI
53AQI
4th August 2025
48AQI
48AQI
5th August 2025
55AQI
55AQI
6th August 2025
57AQI
57AQI
29AQI
32AQI
34AQI
30AQI
26AQI
47AQI
41AQI
68AQI
No. of days
Jan.Feb.Mar.Apr.MayJun.Jul.Aug.Sep.Oct.Nov.Dec.Total Days
202535AQI
29
2
27
1
28
3
29
1
31
17
13
25
6
1
4
1
187
30
1
Highest AQI recorded in
August68AQI
Lowest AQI recorded in
May26AQI
202434AQI
31
23
6
29
2
30
30
1
25
4
24
7
25
6
28
2
27
4
30
29
2
331
34
Highest AQI recorded in
July40AQI
Lowest AQI recorded in
November27AQI
202343AQI
23
8
27
1
26
5
28
2
26
5
5
23
1
1
18
12
1
20
11
26
4
29
2
28
1
28
3
284
77
2
1
Highest AQI recorded in
June74AQI
Lowest AQI recorded in
December30AQI
202239AQI
26
5
17
4
27
4
29
1
27
4
24
6
20
4
2
27
1
29
2
23
7
20
11
271
49
Highest AQI recorded in
June44AQI
Lowest AQI recorded in
September33AQI
202143AQI
26
4
23
5
24
7
26
4
29
2
24
6
12
16
3
20
10
1
22
8
28
3
22
6
19
10
275
81
4
Highest AQI recorded in
July58AQI
Lowest AQI recorded in
October35AQI
202039AQI
11
2
18
2
18
25
5
24
7
29
2
28
1
28
2
24
4
18
11
223
36
Highest AQI recorded in
December44AQI
Lowest AQI recorded in
October34AQI
Most & Least Polluted Years Over the Last 6 Years
Most Polluted Year Recorded
2023(Avg.)
43AQILeast Polluted Year Recorded
2024(Avg.)
34AQIDecatur's annual 2025 AQI (35) shows an average percentage change of -10.2% (improved AQI) compared to previous years: 2020 (39), 2021 (43), 2022 (39), 2023 (43), 2024 (34).
