Air Monitoring Data

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This page provides access to current and historical air quality and meteorological information based on measurements taken at stations in the Air District’s air monitoring network. Some of the data on these pages is raw or unchecked data that may contain errors.

Measurement: PM2.5

PM2.5 is a term for fine particulate matter pollution.  PM2.5 is primarily a problem in the wintertime in the Bay Area, when wood burning constitutes the major source.

Daily AQI Measurements

Each cell in this chart shows the estimated hourly Air Quality Index (AQI) values for PM2.5.  

As established by the U.S. EPA, the AQI for PM2.5 is based on 24-hour concentrations, so hourly readings are only estimates.  

The column at far right shows the preliminary AQI value for the day, based on the 24-hour average concentration.

If the number in the far right column is greater than 100, it means that PM2.5 levels were over the federal health standard.  Values between 101 and 150 in the far right column mean that air quality was in the Unhealthy for Sensitive Groups category for the day.  If the value in the far right column is greater than 150, that means air quality was in the Unhealthy category.

* At this time, PM2.5 measurements at the Napa Valley College location are for informational purposes only.

AQI Key 
Northern Zone
Stations Sunday, September 23, 2018
Hourly PST 01234567891011121314151617181920212223
Napa - Napa Valley College
52
32
18
24
31
26
17
8
15
20
31
34
36
32
35
40
45
52
Sebastopol
18
13
0
0
0
3
0
0
0
0
0
0
4
12
19
26
40
41
Vallejo
25
31
32
27
22
25
21
25
31
39
38
34
35
39
48
52
53
54
Coast & Central Bay
Stations Sunday, September 23, 2018
Hourly PST 01234567891011121314151617181920212223
Berkeley Aquatic Park
15
18
18
15
14
11
18
30
30
38
44
47
44
51
47
48
57
58
Laney College
32
35
34
34
35
41
53
54
54
58
58
57
58
57
60
62
64
64
Oakland East
26
25
27
24
18
15
14
15
20
29
27
34
36
43
45
43
51
55
Oakland West
19
26
42
40
32
29
33
55
64
59
60
66
66
70
63
62
69
59
San Francisco - Arkansas St.
48
36
35
32
35
36
32
43
36
37
41
35
34
53
44
39
52
47
San Pablo - Rumrill
32
35
36
28
29
29
29
29
42
48
53
56
57
57
62
66
67
70
Eastern Zone
Stations Sunday, September 23, 2018
Hourly PST 01234567891011121314151617181920212223
Concord
9
5
8
10
10
7
5
9
11
10
11
10
15
18
18
15
14
17
Livermore - Rincon Ave.
31
30
27
20
22
28
29
29
27
30
32
26
24
26
24
16
12
12
Pleasanton - Owens Ct
45
45
43
36
27
28
26
24
30
45
41
37
38
44
40
31
28
28
South Central Bay
Stations Sunday, September 23, 2018
Hourly PST 01234567891011121314151617181920212223
Redwood City
18
18
13
0
0
0
5
5
25
38
56
54
51
54
54
46
40
47
Santa Clara Valley
Stations Sunday, September 23, 2018
Hourly PST 01234567891011121314151617181920212223
San Jose - Jackson St.
32
49
52
51
51
53
52
56
55
53
48
55
52
42
40
52
43
38
San Jose - Knox Av
18
27
39
49
47
51
44
45
39
40
35
34
30
27
30
32
28
43
Spare the Air Status
Spare the Air Status
  • Sunday,
    9/23

    No Spare the Air Alert in Effect

  • Monday,
    9/24

    No Spare the Air Alert in Effect

9/10/2018