Country Background
HistoryAQIPM2.5PM10COSO2NO2O3

Hayward, 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

Hayward, California, United States

2025
AQI
.
Days

AQI Trends: Highest and Lowest

Highest AQI recorded on
18th Oct 2025
57AQI
Lowest AQI recorded on
25th Oct 2025
22AQI

Same Day Analysis (31st October ):
On this day, AQI across the 1 years varied significantly: 2025 ranks 1st highest AQI at 46 of Good air quality on the same day.

Download 2024 Annual Data

World Air Quality Report

Globe

2025 Days Vs Air Quality

Hayward, California, United States

2025

97%

213

3%

7

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

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

Under WHO’s Safe Air Quality Limits: 97%

Health Risk Level:

Very Low

In 2025, 97% 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

Hayward, 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
2nd January 2025
3rd January 2025
4th January 2025
5th January 2025
6th January 2025
7th January 2025
8th January 2025
9th January 2025
10th January 2025
11th January 2025
12th January 2025
13th January 2025
14th January 2025
15th January 2025
16th January 2025
17th January 2025
18th January 2025
19th January 2025
20th January 2025
21st January 2025
22nd January 2025
23rd January 2025
24th January 2025
25th January 2025
26th January 2025
27th January 2025
28th January 2025
29th January 2025
30th January 2025
31st January 2025
1st February 2025
2nd February 2025
3rd February 2025
4th February 2025
5th February 2025
6th February 2025
7th February 2025
8th February 2025
9th February 2025
10th February 2025
11th February 2025
12th February 2025
13th February 2025
14th February 2025
15th February 2025
16th February 2025
17th February 2025
18th February 2025
19th February 2025
20th February 2025
21st February 2025
22nd February 2025
23rd February 2025
24th February 2025
25th February 2025
26th February 2025
27th February 2025
28th February 2025
1st March 2025
2nd March 2025
3rd March 2025
4th March 2025
5th March 2025
6th March 2025
7th March 2025
8th March 2025
9th March 2025
10th March 2025
11th March 2025
12th March 2025
13th March 2025
14th March 2025
15th March 2025
16th March 2025
17th March 2025
18th March 2025
19th March 2025
20th March 2025
21st March 2025
22nd March 2025
23rd March 2025
24th March 2025
25th March 2025
26th March 2025
22AQI
27th March 2025
20AQI
28th March 2025
20AQI
29th March 2025
17AQI
30th March 2025
18AQI
31st March 2025
18AQI
1st April 2025
18AQI
2nd April 2025
19AQI
3rd April 2025
19AQI
4th April 2025
21AQI
5th April 2025
20AQI
6th April 2025
20AQI
7th April 2025
17AQI
8th April 2025
17AQI
9th April 2025
18AQI
10th April 2025
24AQI
11th April 2025
22AQI
12th April 2025
26AQI
13th April 2025
27AQI
14th April 2025
29AQI
15th April 2025
29AQI
16th April 2025
27AQI
17th April 2025
24AQI
18th April 2025
24AQI
19th April 2025
24AQI
20th April 2025
26AQI
21st April 2025
23AQI
22nd April 2025
24AQI
23rd April 2025
30AQI
24th April 2025
30AQI
25th April 2025
19AQI
26th April 2025
15AQI
27th April 2025
14AQI
28th April 2025
20AQI
29th April 2025
26AQI
30th April 2025
28AQI
1st May 2025
30AQI
2nd May 2025
25AQI
3rd May 2025
24AQI
4th May 2025
37AQI
5th May 2025
34AQI
6th May 2025
33AQI
7th May 2025
36AQI
8th May 2025
33AQI
9th May 2025
27AQI
10th May 2025
26AQI
11th May 2025
22AQI
12th May 2025
18AQI
13th May 2025
15AQI
14th May 2025
18AQI
15th May 2025
21AQI
16th May 2025
23AQI
17th May 2025
22AQI
18th May 2025
21AQI
19th May 2025
26AQI
20th May 2025
21AQI
21st May 2025
26AQI
22nd May 2025
27AQI
23rd May 2025
22AQI
24th May 2025
25AQI
25th May 2025
22AQI
26th May 2025
20AQI
27th May 2025
22AQI
28th May 2025
31AQI
29th May 2025
20AQI
30th May 2025
30AQI
31st May 2025
36AQI
1st June 2025
35AQI
2nd June 2025
37AQI
3rd June 2025
30AQI
4th June 2025
35AQI
5th June 2025
32AQI
6th June 2025
24AQI
7th June 2025
24AQI
8th June 2025
23AQI
9th June 2025
21AQI
10th June 2025
26AQI
11th June 2025
36AQI
12th June 2025
39AQI
13th June 2025
36AQI
14th June 2025
30AQI
15th June 2025
31AQI
16th June 2025
30AQI
17th June 2025
30AQI
18th June 2025
30AQI
19th June 2025
36AQI
20th June 2025
39AQI
21st June 2025
33AQI
22nd June 2025
29AQI
23rd June 2025
29AQI
24th June 2025
24AQI
25th June 2025
24AQI
26th June 2025
27AQI
27th June 2025
32AQI
28th June 2025
38AQI
29th June 2025
31AQI
30th June 2025
28AQI
1st July 2025
29AQI
2nd July 2025
29AQI
3rd July 2025
33AQI
4th July 2025
30AQI
5th July 2025
38AQI
6th July 2025
30AQI
7th July 2025
30AQI
8th July 2025
26AQI
9th July 2025
22AQI
10th July 2025
30AQI
11th July 2025
46AQI
12th July 2025
50AQI
13th July 2025
48AQI
14th July 2025
45AQI
15th July 2025
38AQI
16th July 2025
30AQI
17th July 2025
31AQI
18th July 2025
25AQI
19th July 2025
26AQI
20th July 2025
26AQI
21st July 2025
26AQI
22nd July 2025
18AQI
23rd July 2025
16AQI
24th July 2025
16AQI
25th July 2025
17AQI
26th July 2025
17AQI
27th July 2025
17AQI
28th July 2025
20AQI
29th July 2025
23AQI
30th July 2025
24AQI
31st July 2025
29AQI
1st August 2025
31AQI
2nd August 2025
26AQI
3rd August 2025
35AQI
4th August 2025
41AQI
5th August 2025
42AQI
6th August 2025
40AQI
7th August 2025
30AQI
8th August 2025
31AQI
9th August 2025
45AQI
10th August 2025
42AQI
11th August 2025
36AQI
12th August 2025
38AQI
13th August 2025
38AQI
14th August 2025
31AQI
15th August 2025
34AQI
16th August 2025
24AQI
17th August 2025
21AQI
18th August 2025
22AQI
19th August 2025
28AQI
20th August 2025
28AQI
21st August 2025
36AQI
22nd August 2025
43AQI
23rd August 2025
45AQI
24th August 2025
43AQI
25th August 2025
36AQI
26th August 2025
41AQI
27th August 2025
44AQI
28th August 2025
42AQI
29th August 2025
39AQI
30th August 2025
38AQI
31st August 2025
42AQI
1st September 2025
36AQI
2nd September 2025
42AQI
3rd September 2025
37AQI
4th September 2025
28AQI
5th September 2025
35AQI
6th September 2025
37AQI
7th September 2025
29AQI
8th September 2025
22AQI
9th September 2025
19AQI
10th September 2025
20AQI
11th September 2025
24AQI
12th September 2025
30AQI
13th September 2025
37AQI
14th September 2025
35AQI
15th September 2025
33AQI
16th September 2025
36AQI
17th September 2025
31AQI
18th September 2025
34AQI
19th September 2025
36AQI
20th September 2025
36AQI
21st September 2025
33AQI
22nd September 2025
33AQI
23rd September 2025
36AQI
24th September 2025
38AQI
25th September 2025
46AQI
26th September 2025
52AQI
27th September 2025
53AQI
28th September 2025
30AQI
29th September 2025
17AQI
30th September 2025
17AQI
1st October 2025
24AQI
2nd October 2025
29AQI
3rd October 2025
39AQI
4th October 2025
52AQI
5th October 2025
50AQI
6th October 2025
49AQI
7th October 2025
46AQI
8th October 2025
45AQI
9th October 2025
36AQI
10th October 2025
37AQI
11th October 2025
31AQI
12th October 2025
31AQI
13th October 2025
47AQI
14th October 2025
32AQI
15th October 2025
38AQI
16th October 2025
45AQI
17th October 2025
49AQI
18th October 2025
57AQI
19th October 2025
56AQI
20th October 2025
52AQI
21st October 2025
51AQI
22nd October 2025
39AQI
23rd October 2025
44AQI
24th October 2025
28AQI
25th October 2025
22AQI
26th October 2025
31AQI
27th October 2025
22AQI
28th October 2025
30AQI
29th October 2025
45AQI
30th October 2025
49AQI
31st October 2025
46AQI
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

19AQI

23AQI

26AQI

31AQI

29AQI

36AQI

33AQI

40AQI

No. of days

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

202531AQI

6
30
31
30
31
31
28
2
26
5
213
7

Highest AQI recorded in

October

40AQI

Lowest AQI recorded in

March

19AQI

Most & Least Polluted Years Over the Last 1 Years

Most Polluted Year Recorded
2025(Avg.)
31AQI
Least Polluted Year Recorded
2025(Avg.)
31AQI

Hayward's annual 2025 AQI (31) shows an average percentage change of NaN% (improved AQI) compared to previous years: .