Fog in San Francisco!

Topic:
Meteorology

Type of Web activity:
Getting data and activities from the Web

Materials / Software needed:
Depends on activity / Web browser

Grade Level:
5-12

Time involved:
One class period

Created:
July 1996

Updated:
July 2010

This site developed and maintained by Eric Muller .

3601 Lyon St.
San Francisco, CA 94123

© The Exploratorium

When warm Pacfic air cools, water vapor condenses to form a mist. When this mist is on the earth's surface it's called fog....and San Francisco has a lot of it.

Fog forms off the coast of San Francisco. Air in the coastal valleys of the Bay Area and the Central Valley of California heats up during the day. The air in these locations expand and rise. This displaced air must be replaced. Air is drawn in* from offshore where fog has formed. This fog travels through the Golden Gate. San Francisco just happens to be in the path of this "replacement air." The fog gets carried along as the air makes its way towards the hotter regions of the Bay Area.

Below are a some links that can be made into a lesson.

• Link to a hands-on fog making activity.
• Fog related exhibits at the Exploratorium
• See if there is fog in San Francisco.
  • Exploratorium Roof Camera
  • San Francisco Web Cameras
• Weather conditions at the Exploratorium
• Weather and wind speed in the Central Valley of California (Sacramento)
• What's the weather in the rest of California
• Fog Forecast
• More info on weather

*Areas of higher air pressure tend to flow towards areas of lower air pressure.