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.  View AQI flyer.

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.

Refresh this page to view the current day.


AQI Key 
Northern Zone
Stations Friday, April 19, 2019
Hourly PST 01234567891011121314151617181920212223
Napa - Napa Valley College
17
15
14
13
15
18
15
20
20
San Rafael
26
27
29
23
18
18
27
30
30
Sebastopol
10
11
12
14
9
9
11
8
10
Vallejo
38
33
31
24
14
24
30
30
30
Coast & Central Bay
Stations Friday, April 19, 2019
Hourly PST 01234567891011121314151617181920212223
Berkeley Aquatic Park
3
12
18
15
14
18
21
23
26
Laney College
9
13
15
12
12
12
10
15
16
Oakland East
15
10
13
19
16
14
24
32
45
Oakland West
3
8
20
21
17
12
8
17
25
San Francisco - Arkansas St.
26
25
21
15
12
14
18
27
30
San Pablo - Rumrill
13
11
12
16
16
19
22
25
23
Eastern Zone
Stations Friday, April 19, 2019
Hourly PST 01234567891011121314151617181920212223
Concord
30
32
37
33
31
32
39
38
38
Livermore - Rincon Ave.
29
35
36
33
33
35
36
39
40
Pleasanton - Owens Ct
36
35
61
51
49
45
43
42
40
South Central Bay
Stations Friday, April 19, 2019
Hourly PST 01234567891011121314151617181920212223
Redwood City
33
32
30
23
12
54
52
50
33
Santa Clara Valley
Stations Friday, April 19, 2019
Hourly PST 01234567891011121314151617181920212223
Gilroy
4
6
8
14
18
17
21
27
32
San Jose - Jackson St.
52
48
40
41
43
56
57
57
59
San Jose - Knox Av
25
23
18
19
22
24
30
40
39
Wood Burning Status
Wood Burning Status
  • Friday,
    4/19

    No Spare the Air Alert in Effect