Bay Area Images

Scenic View

The Air District has a good track record, but with appropriate foresight and planning, we can do more. To succeed, it will take leadership, an integrated approach – from cutting edge science to implementation of smart growth measures – even stronger relationships with all of the Air District’s partners and the active engagement of communities and individual citizens

Give Us Your Feedback



select


(500 character limit)
 

I would like a response.
(Allow 5-7 business days)
 

 

Utility Buttons

  • Email This Page
  • Print
  • Save & Share Share

Spare the Air Status

Tuesday, 5/22
No Spare the Air Alert in Effect
Wednesday, 5/23
No Spare the Air Alert in Effect
Spare the Air Logo
Air Quality Widgets | BAAQMD

BAAQMD Webcasts

Recent Webcasts

5/16/2012
Board of Directors Special Meeting
More Information:
5/16/2012 Agenda
(442 kb PDF, 8 pgs)

5/2/2012 Board of Directors Meeting
More Information:
5/2/2012 Agenda
(1 Mb PDF, 52 pgs)

4/18/2012 Board of Directors Meeting
More Information:
4/18/2012 Agenda
(4 Mb PDF, 315 pgs)

Board Archives

Agendas, Minutes and Media

HelpWebcast Support
System & player requirements, RSS feeds & mobile alternatives.

BAAQMD on iTunes

iTunes Audio Podcasts
iTunes Video Podcasts

Precipitation

The San Francisco Bay Area climate is characterized by moderately wet winters and dry summers. Winter rains (December through March) account for about 75 percent of the average annual rainfall; about 90 percent of the annual total rainfall is received in the November-April period; and between 15 June and 22 September, normal rainfall is typically less than 1/10 inch. Annual precipitation amounts show great differences in short distances.

Annual totals exceed 40 inches in the mountains and are less than 15 inches in the sheltered or 'shadowed' valleys. The frequency of winter rain is more uniform, however, with 10 days per month (December through March) being typical.

During rainy periods, ventilation and vertical mixing are usually high, and consequently pollution levels are low. However, there are frequent winter dry periods lasting over a week. It is during some of these periods that CO and particulate pollution episodes develop.

Last Updated: 10/4/2010