• Tonight

    Aug 1

    Lo 60°

    Mainly clear

    Bicycling Weather
    • Precip
      0%
    • Hours of Precip
      0
    • Wind
      Gust
      17 mph
  • Sat

    Aug 2

    81°Lo 60°

    Mostly sunny

    Excellent for biking
    • Precip
      0%
    • Hours of Precip
      0
    • Wind
      Gust
      12 mph
    more
  • Sun

    Aug 3

    81°Lo 61°

    Mostly sunny

    Excellent for biking
    • Precip
      0%
    • Hours of Precip
      0
    • Wind
      Gust
      12 mph
    more
  • Mon

    Aug 4

    80°Lo 60°

    Mostly sunny

    Excellent for biking
    • Precip
      1%
    • Hours of Precip
      0
    • Wind
      Gust
      11 mph
    more
  • Tue

    Aug 5

    79°Lo 61°

    Mostly sunny

    Excellent for biking
    • Precip
      3%
    • Hours of Precip
      0
    • Wind
      Gust
      12 mph
    more
Next Previous
Hi 83° RealFeel® 84° Precipitation 0%

Day

N

E

S

W

  • WNW 8 mph
  • Gusts: 17 mph

Sunny

  • Max UV Index: 9 (Very High)
  • Thunderstorms: 3%
  • Precipitation: 0 in
  • Rain: 0 in
  • Snow: 0 in
  • Ice: 0 in
  • Hours of Precipitation: 0 hrs
  • Hours of Rain: 0 hrs
Lo 60° RealFeel® 58° Precipitation 0%

Night

N

E

S

W

  • NNW 5 mph
  • Gusts: 14 mph

Mainly clear

  • Max UV Index: N/A
  • Thunderstorms: 1%
  • Precipitation: 0 in
  • Rain: 0 in
  • Snow: 0 in
  • Ice: 0 in
  • Hours of Precipitation: 0 hrs
  • Hours of Rain: 0 hrs

Temperature History - Aug 1

more Historical Weather Data >
  Today Normal Record 8/1/2013
High 83° N/A N/A 70°
Low 60° N/A N/A 54°

Sunrise/Sunset

Sunrise / Sunset Illustration

Rises at 6:12 AM with 14:05 of sunlight, then sets at 8:17 PM

Moonrise/Moonset

Astronomy >
Moonrise / Moonset Illustration

Rises at 11:34 AM with 11:37 of moolight, then sets at 11:11 PM

Top Story

Castro Valley Weather Report

Southwest Storms to Aid Wildfire Efforts

August 2, 2014; 1:11 AM ET

An increase in moisture from the Southwest monsoon will fuel showers and heavy thunderstorms across the interior West through the weekend. 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.