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 Thursday, November 15, 2018 Daily
Hourly PST 01234567891011121314151617181920212223 AQI
Napa - Napa Valley College
153
153
153
152
152
151
151
153
155
153
152
153
153
157
167
167
184
198
206
204
197
189
188
186
170
San Rafael
164
161
160
161
161
161
160
161
164
167
167
171
174
186
198
198
206
204
204
200
196
192
192
193
181
Sebastopol
98
87
89
92
91
90
92
93
92
92
89
122
147
151
155
158
158
166
170
172
172
172
170
169
153
Vallejo
155
155
155
155
155
157
159
160
162
166
167
176
193
207
202
207
207
210
213
217
224
226
224
223
186
Coast & Central Bay
Stations Thursday, November 15, 2018 Daily
Hourly PST 01234567891011121314151617181920212223 AQI
Berkeley Aquatic Park
190
190
188
187
185
185
184
182
182
182
183
194
215
246
247
232
230
225
223
220
217
206
200
198
Laney College
193
194
193
193
192
190
190
186
188
191
190
191
198
217
244
248
235
226
226
226
220
213
206
204
202
Oakland East
192
193
195
195
194
192
192
192
191
192
192
194
194
198
204
219
240
240
230
219
212
209
208
207
203
Oakland West
195
194
192
191
190
190
188
184
182
183
186
191
198
210
237
229
220
217
221
220
220
219
220
219
199
San Francisco - Arkansas St.
187
188
188
184
177
168
163
162
167
175
180
191
211
221
235
244
244
242
240
237
234
229
228
228
197
San Pablo - Rumrill
183
181
180
176
175
172
172
173
176
178
186
197
227
258
263
263
251
229
216
204
200
199
205
203
196
Eastern Zone
Stations Thursday, November 15, 2018 Daily
Hourly PST 01234567891011121314151617181920212223 AQI
Concord
166
166
169
171
171
170
171
172
174
176
177
180
194
192
192
198
200
203
199
197
184
Livermore - Rincon Ave.
196
196
196
201
205
206
206
204
202
196
193
193
196
193
188
184
181
181
185
188
190
192
191
190
193
Pleasanton - Owens Ct
193
193
192
192
192
190
187
188
189
188
187
188
193
197
192
197
197
198
199
199
198
197
194
192
193
South Central Bay
Stations Thursday, November 15, 2018 Daily
Hourly PST 01234567891011121314151617181920212223 AQI
Redwood City
159
160
161
164
166
166
169
170
172
176
178
186
187
190
195
207
212
220
221
218
217
204
191
185
185
Santa Clara Valley
Stations Thursday, November 15, 2018 Daily
Hourly PST 01234567891011121314151617181920212223 AQI
Gilroy
177
177
178
179
180
179
177
176
176
175
174
174
174
173
173
176
176
176
168
164
165
166
166
165
173
San Jose - Jackson St.
182
183
182
181
181
181
180
180
180
180
180
181
182
182
181
185
185
204
222
231
238
232
213
199
191
San Jose - Knox Av
176
176
176
176
176
178
178
178
178
178
178
178
179
179
179
180
180
200
225
227
206
196
191
191
186
Wood Burning Status
Wood Burning Status
  • Monday,
    12/17

    No Spare the Air Alert in Effect