• Early AM

    Jul 31

    Lo 56°

    Increasing clouds

    Driving Weather
    • Precip
      1%
    • Hours of Precip
      0
    • Rain
      0 in
    more
  • Today

    Jul 31

    79°Lo 59°

    Clouds, then sun

    Excellent for driving
    • Precip
      3%
    • Hours of Precip
      0
    • Rain
      0 in
  • Mon

    Aug 1

    78°Lo 57°

    Areas of fog, then sun

    Excellent for driving
    • Precip
      1%
    • Hours of Precip
      0
    • Rain
      0 in
    more
  • Tue

    Aug 2

    78°Lo 55°

    Mostly sunny and nice

    Excellent for driving
    • Precip
      2%
    • Hours of Precip
      0
    • Rain
      0 in
    more
  • Wed

    Aug 3

    79°Lo 56°

    Fog to sun

    Excellent for driving
    • Precip
      2%
    • Hours of Precip
      0
    • Rain
      0 in
    more
Next Previous
Hi 79° RealFeel® 84° Precipitation 2%

Day

N

E

S

W

  • W 8 mph
  • Gusts: 15 mph

Areas of low clouds and fog, then sunshine

  • 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 59° RealFeel® 59° Precipitation 3%

Night

N

E

S

W

  • W 6 mph
  • Gusts: 13 mph

Mainly clear early on, then areas of low clouds and fog

  • Max UV Index: N/A
  • Thunderstorms: 2%
  • Precipitation: 0 in
  • Rain: 0 in
  • Snow: 0 in
  • Ice: 0 in
  • Hours of Precipitation: 0 hrs
  • Hours of Rain: 0 hrs

Temperature History - Jul 31

more Historical Weather Data >
  Today Normal Record 7/31/2015
High 79° 78° N/A 75°
Low 59° 57° N/A 60°

Sunrise/Sunset

Sunrise / Sunset Illustration

Rises at 6:12 AM with 14:05 of sunlight, then sets at 8:17 PM

Moonrise/Moonset

Astronomy >
Moonrise / Moonset Illustration

Rises at 4:05 AM with 14:30 of moolight, then sets at 6:35 PM

Castro Valley Weather Report

Western US: Diminishing heat to aid in firefighting efforts this week

July 31, 2016; 1:27 AM ET

As several large fires continue to rage across the western United States, weather conditions will gradually improve for firefighting efforts this week. more >

Travel Weather Forecast

Jul 31, 2016; 12:08 AM ET United States travel weather forecast

Sun. Travel Weather

48 Hour Precipitation Forecast

Sun. Driving Weather