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
153
152
152
151
153
155
153
152
153
153
157
167
184
193
205
210
206
197
190
188
186
170
San Rafael
164
161
160
161
161
161
160
161
164
167
167
171
174
186
198
204
210
206
205
201
196
192
192
193
181
Sebastopol
98
87
89
92
91
90
92
93
92
92
89
122
147
151
155
158
165
169
172
173
172
172
170
169
153
Vallejo
155
155
155
155
155
157
159
160
162
166
167
176
193
208
202
207
213
213
214
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
192
191
187
189
191
190
191
198
217
244
248
235
226
226
225
219
211
206
204
202
Oakland East
191
192
194
194
193
192
192
191
191
192
192
194
194
198
204
219
240
247
234
222
214
210
209
207
203
Oakland West
195
194
192
191
190
190
188
184
182
183
186
191
198
210
237
229
220
217
221
220
218
218
219
218
199
San Francisco - Arkansas St.
187
188
188
184
177
168
163
162
167
175
180
191
211
221
235
244
245
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
245
242
225
214
203
200
198
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
182
185
188
190
192
191
191
193
Pleasanton - Owens Ct
193
193
192
193
192
190
187
188
189
188
187
188
193
197
192
197
200
201
201
200
199
197
195
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
208
199
190
184
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
177
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
194
214
227
234
239
233
213
199
191
San Jose - Knox Av
176
176
175
175
176
178
178
178
178
178
178
178
179
179
179
180
186
209
229
229
207
197
191
191
186
Spare the Air Status
Spare the Air Status
  • Sunday,
    5/19

    No Spare the Air Alert in Effect

  • Monday,
    5/20

    No Spare the Air Alert in Effect