• Early AM

    Jul 29

    Lo 56°

    Partly to mostly cloudy

    Bicycling Weather
    • Precip
      1%
    • Hours of Precip
      0
    • Wind
      Gust
      17 mph
    more
  • Today

    Jul 29

    83°Lo 57°

    Clouds, then sun

    Excellent for biking
    • Precip
      5%
    • Hours of Precip
      0
    • Wind
      Gust
      10 mph
    more
  • Sat

    Jul 30

    81°Lo 57°

    Mostly sunny

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

    Jul 31

    79°Lo 59°

    Clouds, then sun

    Excellent for biking
    • Precip
      2%
    • Hours of Precip
      0
    • Wind
      Gust
      13 mph
    more
  • Mon

    Aug 1

    79°Lo 57°

    Areas of fog, then sun

    Very Good for biking
    • Precip
      1%
    • Hours of Precip
      0
    • Wind
      Gust
      13 mph
    more
Next Previous
< Previous 8 hours Next 8 hours >
  Sat
9am
10am 11am 12pm 1pm 2pm 3pm 4pm
  9am 10am 11am 12pm 1pm 2pm 3pm 4pm
Forecast
Mostly Sunny
Mostly Sunny
Mostly Sunny
Mostly Sunny
Mostly Sunny
Mostly Sunny
Mostly Sunny
Mostly Sunny
Temp (°F) 65° 68° 72° 76° 78° 80° 81° 79°
RealFeel® 69° 74° 79° 82° 84° 85° 85° 81°
Humidity 72% 63% 58% 56% 51% 47% 45% 47%
   
  9am 10am 11am 12pm 1pm 2pm 3pm 4pm
Rain
 
0%
 
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0%
 
0%
 
0%
 
0%
 
0%
 
0%
Snow
 
0%
 
0%
 
0%
 
0%
 
0%
 
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Ice
 
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  9am 10am 11am 12pm 1pm 2pm 3pm 4pm
Wind (mph) 6 WSW 6 W 7 W 8 W 9 W 10 W 10 W 10 W
UV Index 3 5 6 8 8 8 7 5
Cloud Cover 25% 25% 25% 25% 21% 11% 11% 11%
Dew Point 56° 55° 57° 59° 59° 58° 58° 57°
Middle Grid line 85 F Middle Grid line 80 F Middle Grid line 75 F Middle Grid line 70 F Middle Grid line 65 F Middle Grid line 60 F

Temperature History - Jul 30

more Historical Weather Data >
  Today Normal Record 7/30/2015
High 81° 78° N/A 79°
Low 57° 57° N/A 59°

Sunrise/Sunset

Sunrise / Sunset Illustration

Rises at 6:11 AM with 14:07 of sunlight, then sets at 8:18 PM

Moonrise/Moonset

Astronomy >
Moonrise / Moonset Illustration

Rises at 3:09 AM with 14:31 of moolight, then sets at 5:40 PM

Castro Valley Weather Report

Oppressive heat to envelop western US as late-week highs soar 10 to 15 degrees Fahrenheit above average

July 29, 2016; 3:33 AM ET

Highs will run between 10 and 15 degrees Fahrenheit above average across much of the interior western United States into the upcoming 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.