• Early AM

    Jun 25

    Lo 53°

    Clear

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

    Jun 25

    83°Lo 54°

    Sunny and very warm

    Excellent for biking
    • Precip
      2%
    • Hours of Precip
      0
    • Wind
      Gust
      12 mph
    more
  • Sun

    Jun 26

    80°Lo 56°

    A full day of sunshine

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

    Jun 27

    81°Lo 55°

    Mostly sunny and nice

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

    Jun 28

    83°Lo 55°

    Plenty of sunshine

    Excellent for biking
    • Precip
      2%
    • Hours of Precip
      0
    • Wind
      Gust
      10 mph
Next Previous
Hi 83° RealFeel® 90° Precipitation 2%

Day

N

E

S

W

  • WSW 7 mph
  • Gusts: 12 mph

Plenty of sunshine

  • Max UV Index: 9 (Very High)
  • 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 55° RealFeel® 55° Precipitation 2%

Night

N

E

S

W

  • SW 5 mph
  • Gusts: 10 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 - Jun 28

more Historical Weather Data >
  Today Normal Record 6/28/2015
High 83° 76° N/A 72°
Low 55° 55° N/A 60°

Sunrise/Sunset

Sunrise / Sunset Illustration

Rises at 5:49 AM with 14:45 of sunlight, then sets at 8:34 PM

Moonrise/Moonset

Astronomy >
Moonrise / Moonset Illustration

Rises at 1:29 AM with 12:55 of moolight, then sets at 2:24 PM

Castro Valley Weather Report

Extreme heat to exacerbate southwestern US wildfire threat into next week

June 25, 2016; 4:49 AM ET

Another round of sizzling heat threatens to aggravate the ongoing wildfire situation across the southwestern United States through early 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.