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, November 16, 2018 Daily
Hourly PST 01234567891011121314151617181920212223 AQI
Napa - Napa Valley College
180
180
181
176
175
171
171
171
169
168
170
175
181
186
189
189
192
197
195
195
195
195
194
193
183
San Rafael
195
196
198
199
201
208
218
226
230
230
244
244
220
209
202
202
207
212
218
223
223
224
220
217
218
Sebastopol
172
170
170
171
171
170
169
168
167
165
164
166
166
166
166
167
167
168
170
170
170
170
170
168
Vallejo
223
224
224
224
249
248
246
239
249
258
255
247
238
232
233
239
246
250
252
253
255
254
254
254
247
Coast & Central Bay
Stations Friday, November 16, 2018 Daily
Hourly PST 01234567891011121314151617181920212223 AQI
Berkeley Aquatic Park
194
192
191
190
188
187
187
189
193
199
206
233
246
256
245
233
230
231
230
234
239
241
236
232
216
Laney College
194
189
188
191
191
193
196
197
206
216
211
211
230
245
247
234
232
231
230
239
242
240
236
231
219
Oakland East
208
206
204
202
199
200
200
199
202
207
209
206
201
200
212
235
246
246
250
247
249
248
249
248
222
Oakland West
217
213
210
206
197
195
195
196
198
204
205
222
233
245
235
225
222
226
227
231
232
236
240
241
220
San Francisco - Arkansas St.
224
221
217
215
213
215
221
226
233
235
238
239
245
263
271
266
247
229
219
208
206
205
209
209
228
San Pablo - Rumrill
202
203
203
205
205
226
249
282
285
276
291
323
267
238
227
228
233
235
240
245
250
247
239
236
245
Eastern Zone
Stations Friday, November 16, 2018 Daily
Hourly PST 01234567891011121314151617181920212223 AQI
Concord
259
255
252
241
236
233
231
229
228
228
228
228
225
230
Livermore - Rincon Ave.
189
187
182
180
178
176
175
176
175
175
181
243
282
241
233
241
289
293
303
297
288
277
273
262
223
Pleasanton - Owens Ct
187
185
185
183
180
179
179
179
181
182
193
219
224
234
248
265
287
289
276
259
248
248
245
243
215
South Central Bay
Stations Friday, November 16, 2018 Daily
Hourly PST 01234567891011121314151617181920212223 AQI
Redwood City
183
179
172
172
170
171
171
171
174
177
186
193
193
188
191
194
199
203
205
202
195
189
175
166
183
Santa Clara Valley
Stations Friday, November 16, 2018 Daily
Hourly PST 01234567891011121314151617181920212223 AQI
Gilroy
165
165
164
162
161
162
161
160
160
161
174
181
180
168
160
157
157
154
148
138
123
111
93
93
158
San Jose - Jackson St.
192
187
184
184
184
183
184
184
183
185
188
191
190
191
192
193
193
194
195
196
196
196
195
192
190
San Jose - Knox Av
189
189
189
190
192
194
195
193
194
197
197
199
198
196
195
194
194
195
195
197
196
194
192
191
194
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