• Today

    Dec 18

    61°Lo 53°

    Spotty showers this morning

    Good for an outdoor bbq
    • Precip
      60%
    • Hi
      RealFeel
      60°
    • Wind
      Gust
      8 mph
    more
  • Fri

    Dec 19

    61°Lo 50°

    Periods of rain

    Poor for an outdoor bbq
    • Precip
      65%
    • Hi
      RealFeel
      58°
    • Wind
      Gust
      10 mph
    more
  • Sat

    Dec 20

    60°Lo 50°

    Times of clouds and sun

    Very Good for an outdoor bbq
    • Precip
      23%
    • Hi
      RealFeel
      61°
    • Wind
      Gust
      5 mph
    more
  • Sun

    Dec 21

    63°Lo 51°

    Mostly cloudy

    Very Good for an outdoor bbq
    • Precip
      7%
    • Hi
      RealFeel
      64°
    • Wind
      Gust
      7 mph
    more
  • Mon

    Dec 22

    64°Lo 47°

    Mostly sunny

    Very Good for an outdoor bbq
    • Precip
      3%
    • Hi
      RealFeel
      65°
    • Wind
      Gust
      7 mph
Next Previous
Hi 64° RealFeel® 65° Precipitation 3%

Day

N

E

S

W

  • N 5 mph
  • Gusts: 7 mph

Mostly sunny

  • Max UV Index: 2 (Low)
  • Thunderstorms: 0%
  • Precipitation: 0 in
  • Rain: 0 in
  • Snow: 0 in
  • Ice: 0 in
  • Hours of Precipitation: 0 hrs
  • Hours of Rain: 0 hrs
Lo 47° RealFeel® 46° Precipitation 3%

Night

N

E

S

W

  • N 4 mph
  • Gusts: 6 mph

Clear

  • Max UV Index: N/A
  • Thunderstorms: 0%
  • Precipitation: 0 in
  • Rain: 0 in
  • Snow: 0 in
  • Ice: 0 in
  • Hours of Precipitation: 0 hrs
  • Hours of Rain: 0 hrs

Temperature History - Dec 22

more Historical Weather Data >
  Today Normal Record 12/22/2013
High 64° N/A N/A 70°
Low 47° N/A N/A 45°

Sunrise/Sunset

Sunrise / Sunset Illustration

Rises at 7:20 AM with 9:34 of sunlight, then sets at 4:54 PM

Moonrise/Moonset

Astronomy >
Moonrise / Moonset Illustration

Rises at 7:40 AM with 10:27 of moolight, then sets at 6:07 PM

Castro Valley Weather Report

San Francisco: Dry Weather Ahead for the Weekend

December 18, 2014; 9:19 AM ET

Conditions will turn dry for San Francisco this weekend and last into next week. more >

Is Your Outdoor Gear Waterproof?

Dec 5, 2012; 5:00 AM ET Now that it's cold enough to hit the slopes, you may want to look more closely at what materials your winter sports gear is made of. As it turns out, not all waterproofing is created equal.

Mon. Outdoor Entertaining

Mon. Wind Maps

Mon. UV Index