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HistoryAQIPM2.5PM10COSO2NO2O3

San Luis Obispo, 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+

October Air Quality Analysis

San Luis Obispo, California, United States

2024
2025
AQI
.
Days

AQI Trends: Highest and Lowest

Highest AQI recorded on
19th Oct 2024
44AQI
Lowest AQI recorded on
2nd Oct 2025
9AQI

Same Day Analysis (31st October ):
On this day, AQI across the 2 years varied significantly: 2025 ranks 1st highest AQI at 31 of Good air quality on the same day.

Download 2024 Annual Data

World Air Quality Report

Globe

2025 Days Vs Air Quality

San Luis Obispo, California, United States

2025

98%

297

2%

7

Total number of days with different AQI categories in last 305 days in 2025 (60 days remaining)

Good
297 Days
Moderate
7 Days
Poor
0 Days
Unhealthy
0 Days
Severe
0 Days
Hazardous
0 Days

Under WHO’s Safe Air Quality Limits: 98%

Health Risk Level:

Very Low

In 2025, 98% of 305 days were within WHO’s safe air quality limits. The risk of health issues is Very Low, but health impacts are still unclear.

Annual Air Quality Insights

San Luis Obispo, 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.

-1th undefined 2025
-1th undefined 2025
-1th undefined 2025
1st January 2025
40AQI
2nd January 2025
37AQI
3rd January 2025
35AQI
4th January 2025
25AQI
5th January 2025
27AQI
6th January 2025
29AQI
7th January 2025
25AQI
8th January 2025
38AQI
9th January 2025
39AQI
10th January 2025
40AQI
11th January 2025
35AQI
12th January 2025
27AQI
13th January 2025
34AQI
14th January 2025
34AQI
15th January 2025
38AQI
16th January 2025
35AQI
17th January 2025
34AQI
18th January 2025
40AQI
19th January 2025
48AQI
20th January 2025
44AQI
21st January 2025
40AQI
22nd January 2025
45AQI
23rd January 2025
44AQI
24th January 2025
44AQI
25th January 2025
41AQI
26th January 2025
29AQI
27th January 2025
24AQI
28th January 2025
31AQI
29th January 2025
34AQI
30th January 2025
38AQI
31st January 2025
39AQI
1st February 2025
32AQI
2nd February 2025
24AQI
3rd February 2025
24AQI
4th February 2025
23AQI
5th February 2025
21AQI
6th February 2025
23AQI
7th February 2025
24AQI
8th February 2025
22AQI
9th February 2025
30AQI
10th February 2025
32AQI
11th February 2025
33AQI
12th February 2025
22AQI
13th February 2025
22AQI
14th February 2025
38AQI
15th February 2025
38AQI
16th February 2025
32AQI
17th February 2025
34AQI
18th February 2025
31AQI
19th February 2025
31AQI
20th February 2025
23AQI
21st February 2025
28AQI
22nd February 2025
39AQI
23rd February 2025
41AQI
24th February 2025
34AQI
25th February 2025
33AQI
26th February 2025
40AQI
27th February 2025
41AQI
28th February 2025
40AQI
1st March 2025
36AQI
2nd March 2025
33AQI
3rd March 2025
32AQI
4th March 2025
25AQI
5th March 2025
23AQI
6th March 2025
22AQI
7th March 2025
33AQI
8th March 2025
30AQI
9th March 2025
27AQI
10th March 2025
27AQI
11th March 2025
29AQI
12th March 2025
30AQI
13th March 2025
23AQI
14th March 2025
26AQI
15th March 2025
45AQI
16th March 2025
44AQI
17th March 2025
30AQI
18th March 2025
36AQI
19th March 2025
29AQI
20th March 2025
30AQI
21st March 2025
38AQI
22nd March 2025
39AQI
23rd March 2025
34AQI
24th March 2025
42AQI
25th March 2025
36AQI
26th March 2025
21AQI
27th March 2025
19AQI
28th March 2025
34AQI
29th March 2025
26AQI
30th March 2025
20AQI
31st March 2025
17AQI
1st April 2025
22AQI
2nd April 2025
28AQI
3rd April 2025
31AQI
4th April 2025
31AQI
5th April 2025
25AQI
6th April 2025
28AQI
7th April 2025
23AQI
8th April 2025
18AQI
9th April 2025
29AQI
10th April 2025
31AQI
11th April 2025
32AQI
12th April 2025
44AQI
13th April 2025
42AQI
14th April 2025
29AQI
15th April 2025
40AQI
16th April 2025
36AQI
17th April 2025
30AQI
18th April 2025
26AQI
19th April 2025
27AQI
20th April 2025
27AQI
21st April 2025
28AQI
22nd April 2025
29AQI
23rd April 2025
31AQI
24th April 2025
40AQI
25th April 2025
22AQI
26th April 2025
15AQI
27th April 2025
16AQI
28th April 2025
30AQI
29th April 2025
28AQI
30th April 2025
22AQI
1st May 2025
18AQI
2nd May 2025
24AQI
3rd May 2025
31AQI
4th May 2025
43AQI
5th May 2025
48AQI
6th May 2025
43AQI
7th May 2025
48AQI
8th May 2025
37AQI
9th May 2025
36AQI
10th May 2025
47AQI
11th May 2025
39AQI
12th May 2025
23AQI
13th May 2025
26AQI
14th May 2025
35AQI
15th May 2025
39AQI
16th May 2025
36AQI
17th May 2025
31AQI
18th May 2025
31AQI
19th May 2025
47AQI
20th May 2025
41AQI
21st May 2025
49AQI
22nd May 2025
51AQI
23rd May 2025
40AQI
24th May 2025
34AQI
25th May 2025
29AQI
26th May 2025
27AQI
27th May 2025
21AQI
28th May 2025
28AQI
29th May 2025
27AQI
30th May 2025
23AQI
31st May 2025
25AQI
1st June 2025
25AQI
2nd June 2025
31AQI
3rd June 2025
30AQI
4th June 2025
35AQI
5th June 2025
23AQI
6th June 2025
20AQI
7th June 2025
27AQI
8th June 2025
20AQI
9th June 2025
20AQI
10th June 2025
23AQI
11th June 2025
41AQI
12th June 2025
50AQI
13th June 2025
48AQI
14th June 2025
49AQI
15th June 2025
44AQI
16th June 2025
47AQI
17th June 2025
46AQI
18th June 2025
45AQI
19th June 2025
47AQI
20th June 2025
50AQI
21st June 2025
47AQI
22nd June 2025
47AQI
23rd June 2025
42AQI
24th June 2025
28AQI
25th June 2025
26AQI
26th June 2025
25AQI
27th June 2025
29AQI
28th June 2025
24AQI
29th June 2025
26AQI
30th June 2025
23AQI
1st July 2025
25AQI
2nd July 2025
21AQI
3rd July 2025
29AQI
4th July 2025
32AQI
5th July 2025
52AQI
6th July 2025
40AQI
7th July 2025
29AQI
8th July 2025
22AQI
9th July 2025
22AQI
10th July 2025
24AQI
11th July 2025
28AQI
12th July 2025
32AQI
13th July 2025
28AQI
14th July 2025
22AQI
15th July 2025
22AQI
16th July 2025
21AQI
17th July 2025
21AQI
18th July 2025
21AQI
19th July 2025
24AQI
20th July 2025
24AQI
21st July 2025
20AQI
22nd July 2025
15AQI
23rd July 2025
16AQI
24th July 2025
16AQI
25th July 2025
16AQI
26th July 2025
16AQI
27th July 2025
17AQI
28th July 2025
20AQI
29th July 2025
28AQI
30th July 2025
33AQI
31st July 2025
28AQI
1st August 2025
22AQI
2nd August 2025
26AQI
3rd August 2025
29AQI
4th August 2025
52AQI
5th August 2025
44AQI
6th August 2025
38AQI
7th August 2025
31AQI
8th August 2025
27AQI
9th August 2025
36AQI
10th August 2025
32AQI
11th August 2025
31AQI
12th August 2025
36AQI
13th August 2025
29AQI
14th August 2025
22AQI
15th August 2025
23AQI
16th August 2025
21AQI
17th August 2025
20AQI
18th August 2025
29AQI
19th August 2025
37AQI
20th August 2025
41AQI
21st August 2025
51AQI
22nd August 2025
60AQI
23rd August 2025
41AQI
24th August 2025
36AQI
25th August 2025
39AQI
26th August 2025
45AQI
27th August 2025
43AQI
28th August 2025
43AQI
29th August 2025
34AQI
30th August 2025
41AQI
31st August 2025
51AQI
1st September 2025
49AQI
2nd September 2025
39AQI
3rd September 2025
39AQI
4th September 2025
32AQI
5th September 2025
29AQI
6th September 2025
32AQI
7th September 2025
30AQI
8th September 2025
20AQI
9th September 2025
21AQI
10th September 2025
19AQI
11th September 2025
31AQI
12th September 2025
42AQI
13th September 2025
43AQI
14th September 2025
36AQI
15th September 2025
28AQI
16th September 2025
29AQI
17th September 2025
29AQI
18th September 2025
42AQI
19th September 2025
42AQI
20th September 2025
41AQI
21st September 2025
37AQI
22nd September 2025
31AQI
23rd September 2025
37AQI
24th September 2025
43AQI
25th September 2025
31AQI
26th September 2025
32AQI
27th September 2025
39AQI
28th September 2025
37AQI
29th September 2025
47AQI
30th September 2025
51AQI
1st October 2025
15AQI
2nd October 2025
9AQI
3rd October 2025
18AQI
4th October 2025
18AQI
5th October 2025
13AQI
6th October 2025
12AQI
7th October 2025
15AQI
8th October 2025
14AQI
9th October 2025
11AQI
10th October 2025
13AQI
11th October 2025
18AQI
12th October 2025
22AQI
13th October 2025
19AQI
14th October 2025
14AQI
15th October 2025
10AQI
16th October 2025
14AQI
17th October 2025
15AQI
18th October 2025
20AQI
19th October 2025
14AQI
20th October 2025
21AQI
21st October 2025
36AQI
22nd October 2025
37AQI
23rd October 2025
29AQI
24th October 2025
29AQI
25th October 2025
22AQI
26th October 2025
24AQI
27th October 2025
29AQI
28th October 2025
41AQI
29th October 2025
31AQI
30th October 2025
32AQI
31st October 2025
31AQI
1st November 2025
2nd November 2025
3rd November 2025
4th November 2025
5th November 2025
6th November 2025
7th November 2025
8th November 2025
9th November 2025
10th November 2025
11th November 2025
12th November 2025
13th November 2025
14th November 2025
15th November 2025
16th November 2025
17th November 2025
18th November 2025
19th November 2025
20th November 2025
21st November 2025
22nd November 2025
23rd November 2025
24th November 2025
25th November 2025
26th November 2025
27th November 2025
28th November 2025
29th November 2025
30th November 2025
1st December 2025
2nd December 2025
3rd December 2025
4th December 2025
5th December 2025
6th December 2025
7th December 2025
8th December 2025
9th December 2025
10th December 2025
11th December 2025
12th December 2025
13th December 2025
14th December 2025
15th December 2025
16th December 2025
17th December 2025
18th December 2025
19th December 2025
20th December 2025
21st December 2025
22nd December 2025
23rd December 2025
24th December 2025
25th December 2025
26th December 2025
27th December 2025
28th December 2025
29th December 2025
30th December 2025
31st December 2025

36AQI

31AQI

30AQI

29AQI

35AQI

35AQI

25AQI

36AQI

35AQI

21AQI

No. of days

Jan.Feb.Mar.Apr.MayJun.Jul.Aug.Sep.Oct.Nov.Dec.Total Days

202531AQI

31
28
31
30
30
1
30
30
1
27
4
29
1
31
297
7

Highest AQI recorded in

January

36AQI

Lowest AQI recorded in

October

21AQI

202430AQI

16
1
2
2
12
29
31
31
28
31
29
1
30
1
242
2

Highest AQI recorded in

December

35AQI

Lowest AQI recorded in

February

9AQI

202326AQI

3
31
34

Highest AQI recorded in

November

29AQI

Lowest AQI recorded in

December

26AQI

202125AQI

13
13

Highest AQI recorded in

January

25AQI

Lowest AQI recorded in

January

25AQI

202035AQI

13
20
18
29
1
30
1
24
4
3
18
7
3
2
23
5
2
30
30
1
235
19
8
2

Highest AQI recorded in

September

58AQI

Lowest AQI recorded in

May

27AQI

Most & Least Polluted Years Over the Last 5 Years

Most Polluted Year Recorded
2020(Avg.)
35AQI
Least Polluted Year Recorded
2021(Avg.)
25AQI

San Luis Obispo's annual 2025 AQI (31) shows an average percentage change of 8.7% (worsened AQI) compared to previous years: 2020 (35), 2021 (25), 2023 (26), 2024 (30).