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: Fine Particulate Matter (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.

Refresh this page to view the current day.


AQI Key 
Northern Zone
Stations Monday, June 24, 2019
Hourly PST 01234567891011121314151617181920212223
Napa - Napa Valley College
57
51
40
32
25
22
38
40
37
37
Pleasanton - Owens Ct
30
29
40
51
54
49
52
53
58
45
San Rafael
37
29
27
24
25
22
26
36
32
Sebastopol
30
21
15
18
19
16
10
9
15
30
Vallejo
43
47
38
31
35
32
30
40
37
39
Coast & Central Bay
Stations Monday, June 24, 2019
Hourly PST 01234567891011121314151617181920212223
Berkeley Aquatic Park
40
30
24
20
16
23
24
27
34
38
Laney College
26
18
13
19
22
25
27
26
25
23
Oakland East
43
36
27
28
24
16
19
26
27
Oakland West
38
38
29
25
31
28
20
22
26
27
San Francisco - Arkansas St.
21
17
12
8
19
18
23
30
36
49
San Pablo - Rumrill
34
27
22
19
20
20
29
40
42
38
Eastern Zone
Stations Monday, June 24, 2019
Hourly PST 01234567891011121314151617181920212223
Concord
40
37
35
30
36
37
43
53
52
55
Livermore - Rincon Ave.
33
40
47
51
46
40
51
55
56
61
South Central Bay
Stations Monday, June 24, 2019
Hourly PST 01234567891011121314151617181920212223
Redwood City
40
41
35
28
28
29
35
42
55
58
Santa Clara Valley
Stations Monday, June 24, 2019
Hourly PST 01234567891011121314151617181920212223
Gilroy
48
52
50
45
46
44
40
43
47
51
San Jose - Jackson St.
58
58
54
52
53
53
57
51
51
55
San Jose - Knox Av
45
41
38
38
35
47
44
49
52
49
Spare the Air Status
Spare the Air Status
  • Monday,
    6/24

    No Spare the Air Alert in Effect