Ontario, California, 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
Ontario, California, United States
2021
2022
2023
2024
2025
AQI
.
Days
AQI Trends: Highest and Lowest
Highest AQI recorded on
25th Aug 2021
90AQILowest AQI recorded on
21st Aug 2023
25AQISame Day Analysis (10th August ):
On this day, AQI across the 5 years varied significantly: 2025 ranks 3rd highest AQI at 56 of Moderate air quality, showing improvement over 2024 and 2021 on the same day.
Download 2024 Annual Data
World Air Quality Report
Day & Night AQI Trend: 10th Aug - 11th Aug 2025
Ontario, California, United States
AQI
Day
Night
.
5 AM10th Aug 2025
7 PM
4 AM11th Aug 2025
Day time
Avg. Highest Time
7AM10th Aug
50AQI
Avg. Lowest Time
10AM10th Aug
46AQI
Night time
Avg. Highest Time
1AM11th Aug
53AQI
Avg. Lowest Time
12AM11th Aug
48AQI
In the last 24 hours,
Ontario's AQI reached its highest point of 53 at 1 AM during the Night, while the lowest point, 46, was recorded at 10 AM during the Day between 10th Aug and 11th Aug 2025.
Day & Night AQI Trend : Jul - Aug 2025
Ontario, California, United States
JulAug
12th - 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 - 10th10th - 11th11th
Day
Night
12th Jul 2025465 AMAQI
12th Jul 2025456 AMAQI
12th Jul 2025457 AMAQI
12th Jul 2025468 AMAQI
12th Jul 2025459 AMAQI
12th Jul 20254610 AMAQI
12th Jul 20254611 AMAQI
12th Jul 20254712 PMAQI
12th Jul 2025481 PMAQI
12th Jul 2025482 PMAQI
12th Jul 2025493 PMAQI
12th Jul 2025484 PMAQI
12th Jul 2025485 PMAQI
12th Jul 2025476 PMAQI
12th Jul 2025467 PMAQI
12th Jul 2025468 PMAQI
12th Jul 2025469 PMAQI
12th Jul 20254410 PMAQI
12th Jul 20254511 PMAQI
13th Jul 20254412 AMAQI
13th Jul 2025451 AMAQI
13th Jul 2025442 AMAQI
13th Jul 2025443 AMAQI
13th Jul 2025424 AMAQI
24°C19/31°C
13th Jul 2025445 AMAQI
13th Jul 2025436 AMAQI
13th Jul 2025437 AMAQI
13th Jul 2025478 AMAQI
13th Jul 2025469 AMAQI
13th Jul 20254610 AMAQI
13th Jul 20254611 AMAQI
13th Jul 20254612 PMAQI
13th Jul 2025471 PMAQI
13th Jul 2025462 PMAQI
13th Jul 2025473 PMAQI
13th Jul 2025464 PMAQI
13th Jul 2025455 PMAQI
13th Jul 2025446 PMAQI
13th Jul 2025457 PMAQI
13th Jul 2025448 PMAQI
13th Jul 2025439 PMAQI
13th Jul 20254210 PMAQI
13th Jul 20254011 PMAQI
14th Jul 20254212 AMAQI
14th Jul 2025421 AMAQI
14th Jul 2025402 AMAQI
14th Jul 2025363 AMAQI
14th Jul 2025354 AMAQI
25°C19/32°C
14th Jul 2025365 AMAQI
14th Jul 2025366 AMAQI
14th Jul 2025397 AMAQI
14th Jul 2025408 AMAQI
14th Jul 2025419 AMAQI
14th Jul 20254210 AMAQI
14th Jul 20254611 AMAQI
14th Jul 20254612 PMAQI
14th Jul 2025471 PMAQI
14th Jul 2025472 PMAQI
14th Jul 2025463 PMAQI
14th Jul 2025444 PMAQI
14th Jul 2025425 PMAQI
14th Jul 2025426 PMAQI
14th Jul 2025417 PMAQI
14th Jul 2025418 PMAQI
14th Jul 2025409 PMAQI
14th Jul 20253810 PMAQI
14th Jul 20253711 PMAQI
15th Jul 20253712 AMAQI
15th Jul 2025371 AMAQI
15th Jul 2025382 AMAQI
15th Jul 2025323 AMAQI
15th Jul 2025264 AMAQI
24°C18/33°C
15th Jul 2025265 AMAQI
15th Jul 2025256 AMAQI
15th Jul 2025277 AMAQI
15th Jul 2025308 AMAQI
15th Jul 2025329 AMAQI
15th Jul 20253610 AMAQI
15th Jul 20254011 AMAQI
15th Jul 20254312 PMAQI
15th Jul 2025401 PMAQI
15th Jul 2025402 PMAQI
15th Jul 2025403 PMAQI
15th Jul 2025374 PMAQI
15th Jul 2025375 PMAQI
15th Jul 2025376 PMAQI
15th Jul 2025357 PMAQI
15th Jul 2025368 PMAQI
15th Jul 2025359 PMAQI
15th Jul 20253410 PMAQI
15th Jul 20253311 PMAQI
16th Jul 20253212 AMAQI
16th Jul 2025321 AMAQI
16th Jul 2025312 AMAQI
16th Jul 2025303 AMAQI
16th Jul 2025274 AMAQI
24°C18/31°C
16th Jul 2025285 AMAQI
16th Jul 2025286 AMAQI
16th Jul 2025377 AMAQI
16th Jul 2025348 AMAQI
16th Jul 2025379 AMAQI
16th Jul 20253810 AMAQI
16th Jul 20253811 AMAQI
16th Jul 20254412 PMAQI
16th Jul 2025411 PMAQI
16th Jul 2025382 PMAQI
16th Jul 2025373 PMAQI
16th Jul 2025334 PMAQI
16th Jul 2025325 PMAQI
16th Jul 2025326 PMAQI
16th Jul 2025327 PMAQI
16th Jul 2025318 PMAQI
16th Jul 2025309 PMAQI
16th Jul 20253110 PMAQI
16th Jul 20252911 PMAQI
17th Jul 20252812 AMAQI
17th Jul 2025281 AMAQI
17th Jul 2025282 AMAQI
17th Jul 2025283 AMAQI
17th Jul 2025244 AMAQI
24°C18/31°C
17th Jul 2025275 AMAQI
17th Jul 2025296 AMAQI
17th Jul 2025307 AMAQI
17th Jul 2025328 AMAQI
17th Jul 2025319 AMAQI
17th Jul 20253010 AMAQI
17th Jul 20253311 AMAQI
17th Jul 20253312 PMAQI
17th Jul 2025341 PMAQI
17th Jul 2025432 PMAQI
17th Jul 2025333 PMAQI
17th Jul 2025364 PMAQI
17th Jul 2025365 PMAQI
17th Jul 2025336 PMAQI
17th Jul 2025317 PMAQI
17th Jul 2025318 PMAQI
17th Jul 2025399 PMAQI
17th Jul 20253410 PMAQI
17th Jul 20253211 PMAQI
18th Jul 20253312 AMAQI
18th Jul 2025321 AMAQI
18th Jul 2025312 AMAQI
18th Jul 2025323 AMAQI
18th Jul 2025304 AMAQI
25°C20/33°C
18th Jul 2025305 AMAQI
18th Jul 2025316 AMAQI
18th Jul 2025317 AMAQI
18th Jul 2025308 AMAQI
18th Jul 2025319 AMAQI
18th Jul 20252910 AMAQI
18th Jul 20253211 AMAQI
18th Jul 20253812 PMAQI
18th Jul 2025331 PMAQI
18th Jul 2025362 PMAQI
18th Jul 2025353 PMAQI
18th Jul 2025364 PMAQI
18th Jul 2025355 PMAQI
18th Jul 2025366 PMAQI
18th Jul 2025347 PMAQI
18th Jul 2025348 PMAQI
18th Jul 2025389 PMAQI
18th Jul 20253810 PMAQI
18th Jul 20253911 PMAQI
19th Jul 20253712 AMAQI
19th Jul 2025361 AMAQI
19th Jul 2025342 AMAQI
19th Jul 2025333 AMAQI
19th Jul 2025344 AMAQI
23°C19/30°C
19th Jul 2025375 AMAQI
19th Jul 2025356 AMAQI
19th Jul 2025357 AMAQI
19th Jul 2025368 AMAQI
19th Jul 2025369 AMAQI
19th Jul 20253710 AMAQI
19th Jul 20254111 AMAQI
19th Jul 20254212 PMAQI
19th Jul 2025391 PMAQI
19th Jul 2025402 PMAQI
19th Jul 2025383 PMAQI
19th Jul 2025384 PMAQI
19th Jul 2025375 PMAQI
19th Jul 2025366 PMAQI
19th Jul 2025367 PMAQI
19th Jul 2025388 PMAQI
19th Jul 2025389 PMAQI
19th Jul 20253610 PMAQI
19th Jul 20253311 PMAQI
20th Jul 20253512 AMAQI
20th Jul 2025351 AMAQI
20th Jul 2025352 AMAQI
20th Jul 2025333 AMAQI
20th Jul 2025334 AMAQI
23°C19/31°C
20th Jul 2025355 AMAQI
20th Jul 2025406 AMAQI
20th Jul 2025457 AMAQI
20th Jul 2025428 AMAQI
20th Jul 2025459 AMAQI
20th Jul 20254510 AMAQI
20th Jul 20254411 AMAQI
20th Jul 20254212 PMAQI
20th Jul 2025431 PMAQI
20th Jul 2025442 PMAQI
20th Jul 2025423 PMAQI
20th Jul 2025404 PMAQI
20th Jul 2025405 PMAQI
20th Jul 2025396 PMAQI
20th Jul 2025407 PMAQI
20th Jul 2025408 PMAQI
20th Jul 2025389 PMAQI
20th Jul 20253910 PMAQI
20th Jul 20253811 PMAQI
21st Jul 20253612 AMAQI
21st Jul 2025351 AMAQI
21st Jul 2025362 AMAQI
21st Jul 2025333 AMAQI
21st Jul 2025304 AMAQI
23°C19/30°C
21st Jul 2025335 AMAQI
21st Jul 2025346 AMAQI
21st Jul 2025377 AMAQI
21st Jul 2025378 AMAQI
21st Jul 2025379 AMAQI
21st Jul 20253810 AMAQI
21st Jul 20253611 AMAQI
21st Jul 20253612 PMAQI
21st Jul 2025361 PMAQI
21st Jul 2025362 PMAQI
21st Jul 2025383 PMAQI
21st Jul 2025374 PMAQI
21st Jul 2025385 PMAQI
21st Jul 2025366 PMAQI
21st Jul 2025377 PMAQI
21st Jul 2025358 PMAQI
21st Jul 2025349 PMAQI
21st Jul 20253510 PMAQI
21st Jul 20253411 PMAQI
22nd Jul 20253312 AMAQI
22nd Jul 2025321 AMAQI
22nd Jul 2025322 AMAQI
22nd Jul 2025293 AMAQI
22nd Jul 2025224 AMAQI
21°C18/29°C
22nd Jul 2025255 AMAQI
22nd Jul 2025276 AMAQI
22nd Jul 2025307 AMAQI
22nd Jul 2025328 AMAQI
22nd Jul 2025309 AMAQI
22nd Jul 20253210 AMAQI
22nd Jul 20253411 AMAQI
22nd Jul 20253512 PMAQI
22nd Jul 2025361 PMAQI
22nd Jul 2025342 PMAQI
22nd Jul 2025323 PMAQI
22nd Jul 2025334 PMAQI
22nd Jul 2025355 PMAQI
22nd Jul 2025346 PMAQI
22nd Jul 2025327 PMAQI
22nd Jul 2025328 PMAQI
22nd Jul 2025319 PMAQI
22nd Jul 20253110 PMAQI
22nd Jul 20253211 PMAQI
23rd Jul 20253012 AMAQI
23rd Jul 2025301 AMAQI
23rd Jul 2025282 AMAQI
23rd Jul 2025263 AMAQI
23rd Jul 2025214 AMAQI
21°C18/29°C
23rd Jul 2025235 AMAQI
23rd Jul 2025246 AMAQI
23rd Jul 2025267 AMAQI
23rd Jul 2025278 AMAQI
23rd Jul 2025319 AMAQI
23rd Jul 20253210 AMAQI
23rd Jul 20253211 AMAQI
23rd Jul 20253312 PMAQI
23rd Jul 2025341 PMAQI
23rd Jul 2025342 PMAQI
23rd Jul 2025313 PMAQI
23rd Jul 2025314 PMAQI
23rd Jul 2025325 PMAQI
23rd Jul 2025326 PMAQI
23rd Jul 2025297 PMAQI
23rd Jul 2025298 PMAQI
23rd Jul 2025299 PMAQI
23rd Jul 20252910 PMAQI
23rd Jul 20252911 PMAQI
24th Jul 20252812 AMAQI
24th Jul 2025261 AMAQI
24th Jul 2025292 AMAQI
24th Jul 2025313 AMAQI
24th Jul 2025324 AMAQI
23°C17/31°C
24th Jul 2025325 AMAQI
24th Jul 2025296 AMAQI
24th Jul 2025327 AMAQI
24th Jul 2025308 AMAQI
24th Jul 2025319 AMAQI
24th Jul 20253210 AMAQI
24th Jul 20253711 AMAQI
24th Jul 20254412 PMAQI
24th Jul 2025411 PMAQI
24th Jul 2025372 PMAQI
24th Jul 2025343 PMAQI
24th Jul 2025324 PMAQI
24th Jul 2025305 PMAQI
24th Jul 2025296 PMAQI
24th Jul 2025317 PMAQI
24th Jul 2025318 PMAQI
24th Jul 2025279 PMAQI
24th Jul 20252610 PMAQI
24th Jul 20252611 PMAQI
25th Jul 20252912 AMAQI
25th Jul 2025291 AMAQI
25th Jul 2025282 AMAQI
25th Jul 2025263 AMAQI
25th Jul 2025234 AMAQI
23°C18/31°C
25th Jul 2025235 AMAQI
25th Jul 2025256 AMAQI
25th Jul 2025247 AMAQI
25th Jul 2025248 AMAQI
25th Jul 2025259 AMAQI
25th Jul 20253010 AMAQI
25th Jul 20252911 AMAQI
25th Jul 20252512 PMAQI
25th Jul 2025281 PMAQI
25th Jul 2025272 PMAQI
25th Jul 2025273 PMAQI
25th Jul 2025254 PMAQI
25th Jul 2025265 PMAQI
25th Jul 2025266 PMAQI
25th Jul 2025257 PMAQI
25th Jul 2025268 PMAQI
25th Jul 2025269 PMAQI
25th Jul 20252610 PMAQI
25th Jul 20252511 PMAQI
26th Jul 20252412 AMAQI
26th Jul 2025231 AMAQI
26th Jul 2025232 AMAQI
26th Jul 2025223 AMAQI
26th Jul 2025214 AMAQI
22°C17/29°C
26th Jul 2025205 AMAQI
26th Jul 2025226 AMAQI
26th Jul 2025237 AMAQI
26th Jul 2025248 AMAQI
26th Jul 2025259 AMAQI
26th Jul 20253010 AMAQI
26th Jul 20252611 AMAQI
26th Jul 20252812 PMAQI
26th Jul 2025281 PMAQI
26th Jul 2025282 PMAQI
26th Jul 2025273 PMAQI
26th Jul 2025274 PMAQI
26th Jul 2025285 PMAQI
26th Jul 2025276 PMAQI
26th Jul 2025267 PMAQI
26th Jul 2025258 PMAQI
26th Jul 2025259 PMAQI
26th Jul 20252710 PMAQI
26th Jul 20252711 PMAQI
27th Jul 20252812 AMAQI
27th Jul 2025261 AMAQI
27th Jul 2025252 AMAQI
27th Jul 2025263 AMAQI
27th Jul 2025244 AMAQI
21°C16/27°C
27th Jul 2025245 AMAQI
27th Jul 2025266 AMAQI
27th Jul 2025277 AMAQI
27th Jul 2025308 AMAQI
27th Jul 2025299 AMAQI
27th Jul 20252710 AMAQI
27th Jul 20253111 AMAQI
27th Jul 20253312 PMAQI
27th Jul 2025321 PMAQI
27th Jul 2025312 PMAQI
27th Jul 2025303 PMAQI
27th Jul 2025294 PMAQI
27th Jul 2025285 PMAQI
27th Jul 2025286 PMAQI
27th Jul 2025307 PMAQI
27th Jul 2025298 PMAQI
27th Jul 2025299 PMAQI
27th Jul 20253010 PMAQI
27th Jul 20252811 PMAQI
28th Jul 20252912 AMAQI
28th Jul 2025281 AMAQI
28th Jul 2025272 AMAQI
28th Jul 2025293 AMAQI
28th Jul 2025304 AMAQI
23°C17/30°C
28th Jul 2025275 AMAQI
28th Jul 2025266 AMAQI
28th Jul 2025247 AMAQI
28th Jul 2025248 AMAQI
28th Jul 2025269 AMAQI
28th Jul 20252810 AMAQI
28th Jul 20253011 AMAQI
28th Jul 20253612 PMAQI
28th Jul 2025361 PMAQI
28th Jul 2025372 PMAQI
28th Jul 2025323 PMAQI
28th Jul 2025344 PMAQI
28th Jul 2025315 PMAQI
28th Jul 2025316 PMAQI
28th Jul 2025307 PMAQI
28th Jul 2025318 PMAQI
28th Jul 2025319 PMAQI
28th Jul 20253010 PMAQI
28th Jul 20253011 PMAQI
29th Jul 20252912 AMAQI
29th Jul 2025301 AMAQI
29th Jul 2025302 AMAQI
29th Jul 2025283 AMAQI
29th Jul 2025274 AMAQI
23°C18/31°C
29th Jul 2025285 AMAQI
29th Jul 2025286 AMAQI
29th Jul 2025357 AMAQI
29th Jul 2025298 AMAQI
29th Jul 2025339 AMAQI
29th Jul 20253610 AMAQI
29th Jul 20253811 AMAQI
29th Jul 20254212 PMAQI
29th Jul 2025411 PMAQI
29th Jul 2025442 PMAQI
29th Jul 2025373 PMAQI
29th Jul 2025364 PMAQI
29th Jul 2025345 PMAQI
29th Jul 2025346 PMAQI
29th Jul 2025327 PMAQI
29th Jul 2025358 PMAQI
29th Jul 2025359 PMAQI
29th Jul 20253610 PMAQI
29th Jul 20253411 PMAQI
30th Jul 20253812 AMAQI
30th Jul 2025361 AMAQI
30th Jul 2025342 AMAQI
30th Jul 2025343 AMAQI
30th Jul 2025354 AMAQI
25°C18/34°C
30th Jul 2025365 AMAQI
30th Jul 2025406 AMAQI
30th Jul 2025397 AMAQI
30th Jul 2025428 AMAQI
30th Jul 2025439 AMAQI
30th Jul 20254710 AMAQI
30th Jul 20255111 AMAQI
30th Jul 20255012 PMAQI
30th Jul 2025471 PMAQI
30th Jul 2025472 PMAQI
30th Jul 2025483 PMAQI
30th Jul 2025484 PMAQI
30th Jul 2025485 PMAQI
30th Jul 2025486 PMAQI
30th Jul 2025487 PMAQI
30th Jul 2025488 PMAQI
30th Jul 2025419 PMAQI
30th Jul 20254010 PMAQI
30th Jul 20254011 PMAQI
31st Jul 20254112 AMAQI
31st Jul 2025421 AMAQI
31st Jul 2025452 AMAQI
31st Jul 2025443 AMAQI
31st Jul 2025464 AMAQI
26°C19/34°C
31st Jul 2025465 AMAQI
31st Jul 2025476 AMAQI
31st Jul 2025497 AMAQI
31st Jul 2025518 AMAQI
31st Jul 2025529 AMAQI
31st Jul 20255510 AMAQI
31st Jul 20255611 AMAQI
31st Jul 20255612 PMAQI
31st Jul 2025541 PMAQI
31st Jul 2025552 PMAQI
31st Jul 2025543 PMAQI
31st Jul 2025504 PMAQI
31st Jul 2025475 PMAQI
31st Jul 2025466 PMAQI
31st Jul 2025477 PMAQI
31st Jul 2025448 PMAQI
31st Jul 2025429 PMAQI
31st Jul 20254410 PMAQI
31st Jul 20254611 PMAQI
1st Aug 20254712 AMAQI
1st Aug 2025471 AMAQI
1st Aug 2025462 AMAQI
1st Aug 2025433 AMAQI
1st Aug 2025444 AMAQI
26°C20/34°C
1st Aug 2025455 AMAQI
1st Aug 2025446 AMAQI
1st Aug 2025437 AMAQI
1st Aug 2025468 AMAQI
1st Aug 2025489 AMAQI
1st Aug 20255010 AMAQI
1st Aug 20255211 AMAQI
1st Aug 20255312 PMAQI
1st Aug 2025551 PMAQI
1st Aug 2025572 PMAQI
1st Aug 2025543 PMAQI
1st Aug 2025534 PMAQI
1st Aug 2025525 PMAQI
1st Aug 2025516 PMAQI
1st Aug 2025467 PMAQI
1st Aug 2025468 PMAQI
1st Aug 2025479 PMAQI
1st Aug 20254610 PMAQI
1st Aug 20254211 PMAQI
2nd Aug 20254412 AMAQI
2nd Aug 2025421 AMAQI
2nd Aug 2025412 AMAQI
2nd Aug 2025433 AMAQI
2nd Aug 2025444 AMAQI
25°C19/33°C
2nd Aug 2025435 AMAQI
2nd Aug 2025426 AMAQI
2nd Aug 2025417 AMAQI
2nd Aug 2025438 AMAQI
2nd Aug 2025469 AMAQI
2nd Aug 20254910 AMAQI
2nd Aug 20255111 AMAQI
2nd Aug 20255112 PMAQI
2nd Aug 2025521 PMAQI
2nd Aug 2025552 PMAQI
2nd Aug 2025533 PMAQI
2nd Aug 2025524 PMAQI
2nd Aug 2025535 PMAQI
2nd Aug 2025496 PMAQI
2nd Aug 2025467 PMAQI
2nd Aug 2025488 PMAQI
2nd Aug 2025499 PMAQI
2nd Aug 20254910 PMAQI
2nd Aug 20254811 PMAQI
3rd Aug 20255012 AMAQI
3rd Aug 2025521 AMAQI
3rd Aug 2025532 AMAQI
3rd Aug 2025533 AMAQI
3rd Aug 2025514 AMAQI
26°C19/34°C
3rd Aug 2025515 AMAQI
3rd Aug 2025506 AMAQI
3rd Aug 2025537 AMAQI
3rd Aug 2025548 AMAQI
3rd Aug 2025539 AMAQI
3rd Aug 20255310 AMAQI
3rd Aug 20255411 AMAQI
3rd Aug 20255412 PMAQI
3rd Aug 2025541 PMAQI
3rd Aug 2025542 PMAQI
3rd Aug 2025553 PMAQI
3rd Aug 2025544 PMAQI
3rd Aug 2025525 PMAQI
3rd Aug 2025526 PMAQI
3rd Aug 2025537 PMAQI
3rd Aug 2025518 PMAQI
3rd Aug 2025529 PMAQI
3rd Aug 20255110 PMAQI
3rd Aug 20254911 PMAQI
4th Aug 20255012 AMAQI
4th Aug 2025501 AMAQI
4th Aug 2025492 AMAQI
4th Aug 2025493 AMAQI
4th Aug 2025484 AMAQI
26°C20/34°C
4th Aug 2025495 AMAQI
4th Aug 2025506 AMAQI
4th Aug 2025497 AMAQI
4th Aug 2025498 AMAQI
4th Aug 2025509 AMAQI
4th Aug 20255010 AMAQI
4th Aug 20255211 AMAQI
4th Aug 20255312 PMAQI
4th Aug 2025521 PMAQI
4th Aug 2025542 PMAQI
4th Aug 2025533 PMAQI
4th Aug 2025544 PMAQI
4th Aug 2025575 PMAQI
4th Aug 2025556 PMAQI
4th Aug 2025497 PMAQI
4th Aug 2025518 PMAQI
4th Aug 2025559 PMAQI
4th Aug 20255310 PMAQI
4th Aug 20255411 PMAQI
5th Aug 20255612 AMAQI
5th Aug 2025551 AMAQI
5th Aug 2025552 AMAQI
5th Aug 2025563 AMAQI
5th Aug 2025544 AMAQI
26°C21/33°C
5th Aug 2025525 AMAQI
5th Aug 2025546 AMAQI
5th Aug 2025557 AMAQI
5th Aug 2025588 AMAQI
5th Aug 2025609 AMAQI
5th Aug 20256010 AMAQI
5th Aug 20256111 AMAQI
5th Aug 20256012 PMAQI
5th Aug 2025581 PMAQI
5th Aug 2025602 PMAQI
5th Aug 2025593 PMAQI
5th Aug 2025564 PMAQI
5th Aug 2025545 PMAQI
5th Aug 2025536 PMAQI
5th Aug 2025577 PMAQI
5th Aug 2025538 PMAQI
5th Aug 2025509 PMAQI
5th Aug 20255010 PMAQI
5th Aug 20255211 PMAQI
6th Aug 20255312 AMAQI
6th Aug 2025561 AMAQI
6th Aug 2025552 AMAQI
6th Aug 2025563 AMAQI
6th Aug 2025544 AMAQI
27°C21/35°C
6th Aug 2025565 AMAQI
6th Aug 2025566 AMAQI
6th Aug 2025567 AMAQI
6th Aug 2025578 AMAQI
6th Aug 2025579 AMAQI
6th Aug 20255810 AMAQI
6th Aug 20255811 AMAQI
6th Aug 20255612 PMAQI
6th Aug 2025601 PMAQI
6th Aug 2025602 PMAQI
6th Aug 2025583 PMAQI
6th Aug 2025584 PMAQI
6th Aug 2025565 PMAQI
6th Aug 2025576 PMAQI
6th Aug 2025557 PMAQI
6th Aug 2025578 PMAQI
6th Aug 2025569 PMAQI
6th Aug 20255910 PMAQI
6th Aug 20255711 PMAQI
7th Aug 20255412 AMAQI
7th Aug 2025561 AMAQI
7th Aug 2025552 AMAQI
7th Aug 2025553 AMAQI
7th Aug 2025534 AMAQI
29°C21/37°C
7th Aug 2025545 AMAQI
7th Aug 2025546 AMAQI
7th Aug 2025547 AMAQI
7th Aug 2025548 AMAQI
7th Aug 2025539 AMAQI
7th Aug 20255410 AMAQI
7th Aug 20255711 AMAQI
7th Aug 20255612 PMAQI
7th Aug 2025551 PMAQI
7th Aug 2025552 PMAQI
7th Aug 2025543 PMAQI
7th Aug 2025524 PMAQI
7th Aug 2025525 PMAQI
7th Aug 2025496 PMAQI
7th Aug 2025557 PMAQI
7th Aug 2025538 PMAQI
7th Aug 2025509 PMAQI
7th Aug 20255110 PMAQI
7th Aug 20255111 PMAQI
8th Aug 20255112 AMAQI
8th Aug 2025511 AMAQI
8th Aug 2025512 AMAQI
8th Aug 2025523 AMAQI
8th Aug 2025494 AMAQI
30°C24/40°C
8th Aug 2025505 AMAQI
8th Aug 2025516 AMAQI
8th Aug 2025517 AMAQI
8th Aug 2025528 AMAQI
8th Aug 2025509 AMAQI
8th Aug 20255510 AMAQI
8th Aug 20255511 AMAQI
8th Aug 20255312 PMAQI
8th Aug 2025521 PMAQI
8th Aug 2025522 PMAQI
8th Aug 2025523 PMAQI
8th Aug 2025514 PMAQI
8th Aug 2025495 PMAQI
8th Aug 2025496 PMAQI
8th Aug 2025507 PMAQI
8th Aug 2025518 PMAQI
8th Aug 2025489 PMAQI
8th Aug 20254810 PMAQI
8th Aug 20254811 PMAQI
9th Aug 20254812 AMAQI
9th Aug 2025491 AMAQI
9th Aug 2025492 AMAQI
9th Aug 2025493 AMAQI
9th Aug 2025444 AMAQI
31°C25/39°C
9th Aug 2025455 AMAQI
9th Aug 2025466 AMAQI
9th Aug 2025467 AMAQI
9th Aug 2025468 AMAQI
9th Aug 2025469 AMAQI
9th Aug 20254610 AMAQI
9th Aug 20254611 AMAQI
9th Aug 20254712 PMAQI
9th Aug 2025491 PMAQI
9th Aug 2025502 PMAQI
9th Aug 2025493 PMAQI
9th Aug 2025494 PMAQI
9th Aug 2025495 PMAQI
9th Aug 2025496 PMAQI
9th Aug 2025497 PMAQI
9th Aug 2025488 PMAQI
9th Aug 2025499 PMAQI
9th Aug 20254710 PMAQI
9th Aug 20254811 PMAQI
10th Aug 20254812 AMAQI
10th Aug 2025471 AMAQI
10th Aug 2025482 AMAQI
10th Aug 2025473 AMAQI
10th Aug 2025464 AMAQI
29°C22/37°C
10th Aug 2025485 AMAQI
10th Aug 2025476 AMAQI
10th Aug 2025507 AMAQI
10th Aug 2025488 AMAQI
10th Aug 2025479 AMAQI
10th Aug 20254610 AMAQI
10th Aug 20254811 AMAQI
10th Aug 20254712 PMAQI
10th Aug 2025491 PMAQI
10th Aug 2025492 PMAQI
10th Aug 2025493 PMAQI
10th Aug 2025504 PMAQI
10th Aug 2025495 PMAQI
10th Aug 2025496 PMAQI
10th Aug 2025497 PMAQI
10th Aug 2025498 PMAQI
10th Aug 2025499 PMAQI
10th Aug 20255010 PMAQI
10th Aug 20254911 PMAQI
11th Aug 20254812 AMAQI
11th Aug 2025531 AMAQI
11th Aug 2025522 AMAQI
11th Aug 2025493 AMAQI
11th Aug 2025524 AMAQI
27°C23/35°C
11th Aug 2025505 AMAQI
5 AM11th Aug 2025496 AMAQI
11th Aug 2025477 AMAQI
11th Aug 2025468 AMAQI
11th Aug 2025509 AMAQI
11th Aug 20255510 AMAQI
12 PM
7 PM
12 AM
4 AM
--°C/°C
Day time
Avg. Highest Time
5 AM - 7 PM
42AQI
15 hours / Day
450 hours / Month
Avg. Lowest Time
5 AM - 7 PM
42AQI
15 hours / Day
450 hours / Month
In the last 30 days, during the daytime, the highest AQI was between 5 AM to 7 PM (Avg. 42), while the lowest AQI was between 5 AM to 7 PM (Avg. 42).
Night time
Avg. Highest Time
12 AM - 3 AM
40AQI
4 hours / Day
120 hours / Month
Avg. Lowest Time
4 AM
37AQI
1 hours / Day
30 hours / Month
In the last 30 days, during the daytime, the highest AQI was between 12 AM to 3 AM (Avg. 40), while the lowest AQI was between 4 AM to 4 AM (Avg. 37).
2025 Days Vs Air Quality
Ontario, California, United States
2025
68%
150
32%
71
0.4%
1
Total number of days with different AQI categories in last 223 days in 2025 (142 days remaining)
Good
150 DaysModerate
71 DaysPoor
1 DaysUnhealthy
0 DaysSevere
0 DaysHazardous
0 DaysUnder WHO’s Safe Air Quality Limits: 68%
Health Risk Level:
Moderate
In 2025, 68% of 223 days were within WHO’s safe air quality limits, and 32% exceeded them. The risk of health issues is Moderate, particularly for individuals with respiratory or heart conditions.
Annual Air Quality Insights
Ontario, California, 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
103AQI
103AQI
2nd January 2025
78AQI
78AQI
3rd January 2025
67AQI
67AQI
4th January 2025
93AQI
93AQI
5th January 2025
59AQI
59AQI
6th January 2025
47AQI
47AQI
7th January 2025
50AQI
50AQI
8th January 2025
58AQI
58AQI
9th January 2025
47AQI
47AQI
10th January 2025
54AQI
54AQI
11th January 2025
74AQI
74AQI
12th January 2025
31AQI
31AQI
13th January 2025
31AQI
31AQI
14th January 2025
31AQI
31AQI
15th January 2025
33AQI
33AQI
16th January 2025
37AQI
37AQI
17th January 2025
47AQI
47AQI
18th January 2025
58AQI
58AQI
19th January 2025
73AQI
73AQI
20th January 2025
58AQI
58AQI
21st January 2025
32AQI
32AQI
22nd January 2025
44AQI
44AQI
23rd January 2025
30AQI
30AQI
24th January 2025
40AQI
40AQI
25th January 2025
58AQI
58AQI
26th January 2025
33AQI
33AQI
27th January 2025
33AQI
33AQI
28th January 2025
50AQI
50AQI
29th January 2025
50AQI
50AQI
30th January 2025
60AQI
60AQI
31st January 2025
68AQI
68AQI
1st February 2025
74AQI
74AQI
2nd February 2025
77AQI
77AQI
3rd February 2025
70AQI
70AQI
4th February 2025
56AQI
56AQI
5th February 2025
30AQI
30AQI
6th February 2025
34AQI
34AQI
7th February 2025
25AQI
25AQI
8th February 2025
34AQI
34AQI
9th February 2025
48AQI
48AQI
10th February 2025
47AQI
47AQI
11th February 2025
30AQI
30AQI
12th February 2025
31AQI
31AQI
13th February 2025
23AQI
23AQI
14th February 2025
27AQI
27AQI
15th February 2025
31AQI
31AQI
16th February 2025
41AQI
41AQI
17th February 2025
53AQI
53AQI
18th February 2025
46AQI
46AQI
19th February 2025
50AQI
50AQI
20th February 2025
52AQI
52AQI
21st February 2025
36AQI
36AQI
22nd February 2025
42AQI
42AQI
23rd February 2025
48AQI
48AQI
24th February 2025
56AQI
56AQI
25th February 2025
52AQI
52AQI
26th February 2025
50AQI
50AQI
27th February 2025
36AQI
36AQI
28th February 2025
38AQI
38AQI
1st March 2025
41AQI
41AQI
2nd March 2025
34AQI
34AQI
3rd March 2025
27AQI
27AQI
4th March 2025
35AQI
35AQI
5th March 2025
50AQI
50AQI
6th March 2025
27AQI
27AQI
7th March 2025
32AQI
32AQI
8th March 2025
38AQI
38AQI
9th March 2025
39AQI
39AQI
10th March 2025
39AQI
39AQI
11th March 2025
29AQI
29AQI
12th March 2025
29AQI
29AQI
13th March 2025
22AQI
22AQI
14th March 2025
23AQI
23AQI
15th March 2025
38AQI
38AQI
16th March 2025
46AQI
46AQI
17th March 2025
44AQI
44AQI
18th March 2025
24AQI
24AQI
19th March 2025
27AQI
27AQI
20th March 2025
30AQI
30AQI
21st March 2025
42AQI
42AQI
22nd March 2025
44AQI
44AQI
23rd March 2025
53AQI
53AQI
24th March 2025
55AQI
55AQI
25th March 2025
64AQI
64AQI
26th March 2025
36AQI
36AQI
27th March 2025
34AQI
34AQI
28th March 2025
31AQI
31AQI
29th March 2025
34AQI
34AQI
30th March 2025
34AQI
34AQI
31st March 2025
23AQI
23AQI
1st April 2025
24AQI
24AQI
2nd April 2025
26AQI
26AQI
3rd April 2025
32AQI
32AQI
4th April 2025
32AQI
32AQI
5th April 2025
24AQI
24AQI
6th April 2025
27AQI
27AQI
7th April 2025
35AQI
35AQI
8th April 2025
45AQI
45AQI
9th April 2025
49AQI
49AQI
10th April 2025
52AQI
52AQI
11th April 2025
52AQI
52AQI
12th April 2025
53AQI
53AQI
13th April 2025
57AQI
57AQI
14th April 2025
56AQI
56AQI
15th April 2025
54AQI
54AQI
16th April 2025
41AQI
41AQI
17th April 2025
30AQI
30AQI
18th April 2025
31AQI
31AQI
19th April 2025
36AQI
36AQI
20th April 2025
43AQI
43AQI
21st April 2025
47AQI
47AQI
22nd April 2025
53AQI
53AQI
23rd April 2025
45AQI
45AQI
24th April 2025
43AQI
43AQI
25th April 2025
40AQI
40AQI
26th April 2025
21AQI
21AQI
27th April 2025
19AQI
19AQI
28th April 2025
28AQI
28AQI
29th April 2025
41AQI
41AQI
30th April 2025
52AQI
52AQI
1st May 2025
50AQI
50AQI
2nd May 2025
47AQI
47AQI
3rd May 2025
46AQI
46AQI
4th May 2025
26AQI
26AQI
5th May 2025
33AQI
33AQI
6th May 2025
32AQI
32AQI
7th May 2025
38AQI
38AQI
8th May 2025
48AQI
48AQI
9th May 2025
48AQI
48AQI
10th May 2025
42AQI
42AQI
11th May 2025
42AQI
42AQI
12th May 2025
47AQI
47AQI
13th May 2025
27AQI
27AQI
14th May 2025
31AQI
31AQI
15th May 2025
48AQI
48AQI
16th May 2025
53AQI
53AQI
17th May 2025
41AQI
41AQI
18th May 2025
34AQI
34AQI
19th May 2025
45AQI
45AQI
20th May 2025
51AQI
51AQI
21st May 2025
54AQI
54AQI
22nd May 2025
61AQI
61AQI
23rd May 2025
61AQI
61AQI
24th May 2025
57AQI
57AQI
25th May 2025
55AQI
55AQI
26th May 2025
56AQI
56AQI
27th May 2025
54AQI
54AQI
28th May 2025
49AQI
49AQI
29th May 2025
47AQI
47AQI
30th May 2025
47AQI
47AQI
31st May 2025
49AQI
49AQI
1st June 2025
44AQI
44AQI
2nd June 2025
39AQI
39AQI
3rd June 2025
38AQI
38AQI
4th June 2025
40AQI
40AQI
5th June 2025
41AQI
41AQI
6th June 2025
41AQI
41AQI
7th June 2025
43AQI
43AQI
8th June 2025
45AQI
45AQI
9th June 2025
46AQI
46AQI
10th June 2025
48AQI
48AQI
11th June 2025
47AQI
47AQI
12th June 2025
51AQI
51AQI
13th June 2025
50AQI
50AQI
14th June 2025
52AQI
52AQI
15th June 2025
55AQI
55AQI
16th June 2025
58AQI
58AQI
17th June 2025
59AQI
59AQI
18th June 2025
58AQI
58AQI
19th June 2025
56AQI
56AQI
20th June 2025
55AQI
55AQI
21st June 2025
53AQI
53AQI
22nd June 2025
53AQI
53AQI
23rd June 2025
52AQI
52AQI
24th June 2025
50AQI
50AQI
25th June 2025
48AQI
48AQI
26th June 2025
51AQI
51AQI
27th June 2025
52AQI
52AQI
28th June 2025
52AQI
52AQI
29th June 2025
49AQI
49AQI
30th June 2025
45AQI
45AQI
1st July 2025
49AQI
49AQI
2nd July 2025
48AQI
48AQI
3rd July 2025
45AQI
45AQI
4th July 2025
45AQI
45AQI
5th July 2025
81AQI
81AQI
6th July 2025
60AQI
60AQI
7th July 2025
54AQI
54AQI
8th July 2025
51AQI
51AQI
9th July 2025
47AQI
47AQI
10th July 2025
47AQI
47AQI
11th July 2025
51AQI
51AQI
12th July 2025
53AQI
53AQI
13th July 2025
50AQI
50AQI
14th July 2025
46AQI
46AQI
15th July 2025
38AQI
38AQI
16th July 2025
35AQI
35AQI
17th July 2025
29AQI
29AQI
18th July 2025
32AQI
32AQI
19th July 2025
37AQI
37AQI
20th July 2025
41AQI
41AQI
21st July 2025
39AQI
39AQI
22nd July 2025
33AQI
33AQI
23rd July 2025
29AQI
29AQI
24th July 2025
31AQI
31AQI
25th July 2025
26AQI
26AQI
26th July 2025
26AQI
26AQI
27th July 2025
30AQI
30AQI
28th July 2025
32AQI
32AQI
29th July 2025
37AQI
37AQI
30th July 2025
46AQI
46AQI
31st July 2025
52AQI
52AQI
1st August 2025
51AQI
51AQI
2nd August 2025
49AQI
49AQI
3rd August 2025
54AQI
54AQI
4th August 2025
60AQI
60AQI
5th August 2025
65AQI
65AQI
6th August 2025
66AQI
66AQI
7th August 2025
63AQI
63AQI
8th August 2025
61AQI
61AQI
9th August 2025
57AQI
57AQI
10th August 2025
56AQI
56AQI
52AQI
44AQI
36AQI
40AQI
46AQI
49AQI
43AQI
58AQI
No. of days
Jan.Feb.Mar.Apr.MayJun.Jul.Aug.Sep.Oct.Nov.Dec.Total Days
202545AQI
17
13
1
20
8
28
3
22
8
22
9
16
14
24
7
1
9
150
71
1
Highest AQI recorded in
August58AQI
Lowest AQI recorded in
March36AQI
202450AQI
21
10
27
2
28
3
21
9
15
16
5
24
7
23
1
9
22
8
21
1
11
20
22
8
7
23
1
181
181
2
1
Highest AQI recorded in
December63AQI
Lowest AQI recorded in
March32AQI
202348AQI
27
4
24
4
29
2
15
15
18
13
22
8
2
28
1
12
19
9
21
16
15
22
7
14
16
1
210
152
2
Highest AQI recorded in
July64AQI
Lowest AQI recorded in
March35AQI
202257AQI
15
15
16
5
1
6
25
4
13
6
25
30
2
19
1
10
19
11
20
26
4
21
10
117
186
1
Highest AQI recorded in
June73AQI
Lowest AQI recorded in
November40AQI
202159AQI
11
17
2
7
20
1
19
12
9
21
6
25
10
20
6
24
1
7
24
3
27
18
13
4
19
7
10
16
5
110
238
16
Highest AQI recorded in
November78AQI
Lowest AQI recorded in
March47AQI
202063AQI
5
1
20
11
24
5
1
1
25
4
1
9
20
1
15
16
50
97
10
2
Highest AQI recorded in
September83AQI
Lowest AQI recorded in
July21AQI
Most & Least Polluted Years Over the Last 6 Years
Most Polluted Year Recorded
2020(Avg.)
63AQILeast Polluted Year Recorded
2025(Avg.)
45AQIOntario's annual 2025 AQI (45) shows an average percentage change of -18.2% (improved AQI) compared to previous years: 2020 (63), 2021 (59), 2022 (57), 2023 (48), 2024 (50).
