California, 2009

Winter Weather in California, December 7, 2009

December 7, 2009 · NWS MTR · 1 event in 1 county or zone

A low pressure system moved southward out of western Canada and into California causing snow to fall as low as 350 feet above sea level in San Francisco's East Bay Area. In the East Bay Mountains over six inches of snow was reported.

Where it happened

Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

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The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
1

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS MTR wrote it up.

A low pressure system moved southward out of western Canada and into California causing snow to fall as low as 350 feet above sea level in San Francisco's East Bay Area. In the East Bay Mountains over six inches of snow was reported. Also, small hail was observed throughout the Bay Area.

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

1 winter weather. Local standard time, as filed.

Winter Weather, East Bay Interior Valleys

When
December 7, 3:00 AM PST to 12:00 PM PST
Where
East Bay Interior Valleys forecast zone
Reported by
Newspaper
Coordinates
37.787, -121.934 (the zone’s center; the record gives no point)

A cold winter storm caused snow to fall in San Francisco's East Bay valleys as low as 350 feet above sea level. Locations such as Clayton, Alamo, Orinda, Moraga, Danville, Lamorinda, and the Livermore Valley all reported snow. It may have only been two inches at most, but it was enough to play in and cause some traffic problems.

What these are

Winter Weather
Snow, sleet or freezing rain below warning levels that still caused disruption, damage or casualties.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in California in 2009Every state in 2009This day in weather historyWarnings in California, December 2009

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 203533.