• Today

    May 1

    81°Lo 52°

    Sunny and warmer

    Beneficial weather for colds
    • Avg
      Temp
      67°
    • Avg
      RealFeel
      72°
    • Hi
      RealFeel
      91°
    more
  • Mon

    May 2

    75°Lo 52°

    Low clouds, then sun

    Beneficial weather for colds
    • Avg
      Temp
      64°
    • Avg
      RealFeel
      67°
    • Hi
      RealFeel
      81°
    more
  • Tue

    May 3

    71°Lo 51°

    Beautiful with periods of sun

    Beneficial weather for colds
    • Avg
      Temp
      61°
    • Avg
      RealFeel
      63°
    • Hi
      RealFeel
      75°
    more
  • Wed

    May 4

    65°Lo 52°

    Mostly cloudy

    Beneficial weather for colds
    • Avg
      Temp
      59°
    • Avg
      RealFeel
      58°
    • Hi
      RealFeel
      67°
    more
  • Thu

    May 5

    64°Lo 50°

    An afternoon shower in spots

    Beneficial weather for colds
    • Avg
      Temp
      57°
    • Avg
      RealFeel
      57°
    • Hi
      RealFeel
      65°
Next Previous
Hi 64° RealFeel® 65° Precipitation 40%

Day

N

E

S

W

  • W 10 mph
  • Gusts: 17 mph

Mainly cloudy with a stray shower in the afternoon

  • Max UV Index: 4 (Moderate)
  • Thunderstorms: 20%
  • Precipitation: 0.01 in
  • Rain: 0.01 in
  • Snow: 0 in
  • Ice: 0 in
  • Hours of Precipitation: 0.5 hrs
  • Hours of Rain: 0.5 hrs
Lo 50° RealFeel® 48° Precipitation 10%

Night

N

E

S

W

  • SW 6 mph
  • Gusts: 12 mph

Considerable cloudiness

  • 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 - May 5

more Historical Weather Data >
  Today Normal Record 5/5/2015
High 64° 70° N/A 59°
Low 50° 50° N/A 50°

Sunrise/Sunset

Sunrise / Sunset Illustration

Rises at 6:07 AM with 13:56 of sunlight, then sets at 8:03 PM

Moonrise/Moonset

Astronomy >
Moonrise / Moonset Illustration

Rises at 5:36 AM with 13:24 of moolight, then sets at 7:00 PM

Castro Valley Weather Report

San Francisco: Rain showers may dampen the Bay Area for midweek

May 1, 2016; 7:07 AM ET

There is the potential a storm will dive across California and bring a soaking rain for later next week and weekend. more >

Flu Season is Just Around the Corner

Sep 11, 2012; 2:00 PM ET The peak of flu season may not be until January, but preparations should begin now. Adrienne Veilleux has more.

Thu. Cold & Flu

Thu. UV Index