• Early AM

    Sep 3

    Lo 59°

    Low clouds

    Ragweed Pollen Weather
    • Grass
      Pollen
      1 - Low
    • Ragweed
      Pollen
      1 - Low
    • Tree
      Pollen
      1 - Low
    more
  • Today

    Sep 3

    72°Lo 57°

    Low clouds, then sunshine

    Low ragweed pollen levels
    • Grass
      Pollen
      1 - Low
    • Ragweed
      Pollen
      1 - Low
    • Tree
      Pollen
      1 - Low
  • Fri

    Sep 4

    72°Lo 54°

    Areas of low clouds, then sun

    Low ragweed pollen levels
    • Grass
      Pollen
      1 - Low
    • Ragweed
      Pollen
      1 - Low
    • Tree
      Pollen
      1 - Low
    more
  • Sat

    Sep 5

    78°Lo 54°

    Low clouds, then sunshine

    Low ragweed pollen levels
    • Grass
      Pollen
      1 - Low
    • Ragweed
      Pollen
      1 - Low
    • Tree
      Pollen
      1 - Low
    more
  • Sun

    Sep 6

    84°Lo 56°

    Plenty of sun

    Low ragweed pollen levels
    • Grass
      Pollen
      1 - Low
    • Ragweed
      Pollen
      1 - Low
    • Tree
      Pollen
      1 - Low
    more
Next Previous
Hi 72° RealFeel® 73° Precipitation 3%

Day

N

E

S

W

  • WSW 15 mph
  • Gusts: 23 mph

A cool breeze with low clouds giving way to sunshine

  • Max UV Index: 6 (High)
  • Thunderstorms: 1%
  • Precipitation: 0 in
  • Rain: 0 in
  • Snow: 0 in
  • Ice: 0 in
  • Hours of Precipitation: 0 hrs
  • Hours of Rain: 0 hrs
Lo 57° RealFeel® 53° Precipitation 8%

Night

N

E

S

W

  • SW 8 mph
  • Gusts: 16 mph

Mainly clear early, then areas of low clouds forming

  • 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 - September 3

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

    Low

  • Mold Pollen

    Low

  • Ragweed Pollen

    Low

  • Tree Pollen

    Low

Temperature History - Sep 3

more Historical Weather Data >
  Today Normal Record 9/3/2014
High 72° N/A N/A 76°
Low 57° N/A N/A 60°

Sunrise/Sunset

Sunrise / Sunset Illustration

Rises at 6:40 AM with 12:55 of sunlight, then sets at 7:35 PM

Moonrise/Moonset

Astronomy >
Moonrise / Moonset Illustration

Rises at 11:11 PM with 14:10 of moolight, then sets at 1:21 PM

Castro Valley Weather Report

San Francisco: Sunny Skies, Pleasant Conditions to Last Into Labor Day Weekend

September 3, 2015; 3:13 AM ET

Sunny skies and seasonable conditions will follow low clouds each day through Saturday in the Bay Area. more >

Thu. Pollen

Thu. Dust & Dander

Thu. Wind Maps