• Today

    May 3

    66°Lo 50°

    Low clouds, then sunshine

    Excellent for lawn mowing
    • Hours of Precip
      0
    • Precip
      2%
    • Hi
      RealFeel
      71°
    more
  • Mon

    May 4

    64°Lo 48°

    Areas of low clouds, then sun

    Excellent for lawn mowing
    • Hours of Precip
      0
    • Precip
      1%
    • Hi
      RealFeel
      67°
  • Tue

    May 5

    65°Lo 48°

    Mostly sunny

    Excellent for lawn mowing
    • Hours of Precip
      0
    • Precip
      2%
    • Hi
      RealFeel
      66°
    more
  • Wed

    May 6

    65°Lo 48°

    Sunshine; breezy in the p.m.

    Excellent for lawn mowing
    • Hours of Precip
      0
    • Precip
      6%
    • Hi
      RealFeel
      68°
    more
  • Thu

    May 7

    66°Lo 50°

    Clouds limiting sun

    Excellent for lawn mowing
    • Hours of Precip
      0
    • Precip
      4%
    • Hi
      RealFeel
      68°
    more
Next Previous
Hi 64° RealFeel® 67° Precipitation 1%

Day

N

E

S

W

  • WNW 10 mph
  • Gusts: 20 mph

Areas of low clouds, then sun

  • 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 48° RealFeel® 45° Precipitation 0%

Night

N

E

S

W

  • WSW 8 mph
  • Gusts: 15 mph

Mostly 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 - May 4

more Historical Weather Data >
  Today Normal Record 5/4/2014
High 64° N/A N/A 64°
Low 48° N/A N/A 53°

Sunrise/Sunset

Sunrise / Sunset Illustration

Rises at 6:10 AM with 13:51 of sunlight, then sets at 8:01 PM

Moonrise/Moonset

Astronomy >
Moonrise / Moonset Illustration

Rises at 8:46 PM with 10:38 of moolight, then sets at 7:24 AM

Castro Valley Weather Report

San Francisco: Seasonable Temperatures to Continue Through Week

May 3, 2015; 1:29 AM ET

A pattern of seasonable temperatures will continue through the first part of the new week, with low clouds in the morning and sunny conditions through the afternoon. more >

Why Do Leaves Change Color?

Sep 20, 2011; 5:00 AM ET Why do leaves change from green to beautiful shades of red, orange and yellow in the fall?

Mon. Overnight Freeze

Mon. Degree Days

Mon. Evapotranspiration