• Tonight

    Apr 17

    Lo 53°

    Partly cloudy

    Dust & Dander Weather
    • Grass
      Pollen
      2 - Low
    • Ragweed
      Pollen
      0 - Low
    • Tree
      Pollen
      50 - Moderate
  • Fri

    Apr 18

    67°Lo 49°

    Partly sunny

    Low indoor dust & dander levels
    • Grass
      Pollen
      2 - Low
    • Ragweed
      Pollen
      0 - Low
    • Tree
      Pollen
      50 - Moderate
    more
  • Sat

    Apr 19

    66°Lo 50°

    Sunny to partly cloudy

    Low indoor dust & dander levels
    • Grass
      Pollen
      2 - Low
    • Ragweed
      Pollen
      0 - Low
    • Tree
      Pollen
      50 - Moderate
    more
  • Sun

    Apr 20

    69°Lo 49°

    Partly sunny

    Low indoor dust & dander levels
    • Precip
      0%
    • Wind
      Speed
      6 mph
    • Cloud
      Cover
      26%
    more
  • Mon

    Apr 21

    64°Lo 52°

    Clouds and sun

    Low indoor dust & dander levels
    • Precip
      14%
    • Wind
      Speed
      9 mph
    • Cloud
      Cover
      67%
    more
Next Previous
Hi 68° RealFeel® 70° Precipitation 3%

Day

N

E

S

W

  • W 9 mph
  • Gusts: 20 mph

Partly sunny

  • Max UV Index: 8 (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 53° RealFeel® 50° Precipitation 7%

Night

N

E

S

W

  • W 6 mph
  • Gusts: 11 mph

Partly cloudy

  • 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

Castro Valley Pollen Levels - April 17

  • Extreme
  • Very High
  • High
  • Moderate
  • Low
  • Grass

    Pollen

    Low

  • Weed

    Pollen

    Low

  • Tree

    Pollen

    Moderate

  • Mold

    Pollen

    Low

Temperature History - Apr 17

more Historical Weather Data >
  Today Normal Record 4/17/2013
High 68° N/A N/A 70°
Low 53° N/A N/A 49°

Sunrise/Sunset

Sunrise / Sunset Illustration

Rises at 6:31 AM with 13:15 of sunlight, then sets at 7:46 PM

Moonrise/Moonset

Astronomy >
Moonrise / Moonset Illustration

Rises at 10:34 PM with 10:25 of moolight, then sets at 8:59 AM

Top Story

Castro Valley Weather Report

San Francisco: No Rain in Sight, Morning Clouds to Break for Afternoon Sunshine

April 17, 2014; 12:46 PM ET

For the remainder of the week and into the weekend, morning clouds will give way to mostly sunny skies. more >

Is it a Cold or the Flu?

Apr 7, 2014; 5:00 AM ET Symptoms caused by the common cold can often resemble those associated with the influenza virus, so how do you differentiate between the two?

Thu. Pollen

Thu. Dust & Dander

Thu. Wind Maps