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Personalized Forecasts

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    My Recent Locations

    • Today

      Sep 25

      94° /60°
      Plenty of sun
      • Beneficial
      • weather for arthritis pain
      • Rain: 0 in
      • Hours of Precip: 0
      • UV: 5 - High
      More
    • Mon

      Sep 26

      94° /58°
      Hot with plenty of sun
      • Beneficial
      • weather for arthritis pain
      • Rain: 0 in
      • Hours of Precip: 0
      • UV: 5 - High
      More
    • Tue

      Sep 27

      87° /54°F
      Mostly sunny and very warm
      • Neutral
      • weather for arthritis pain
      • Rain: 0 in
      • Hours of Precip: 0
      • UV: 5 - High
    • Wed

      Sep 28

      78° /54°
      Mostly sunny
      • Neutral
      • weather for arthritis pain
      • Rain: 0 in
      • Hours of Precip: 0
      • UV: 4 - Moderate
      More
    • Thu

      Sep 29

      71° /54°
      Mostly sunny and pleasant
      • Beneficial
      • weather for arthritis pain
      • Rain: 0 in
      • Hours of Precip: 0
      • UV: 4 - Moderate
      More

    Day

    87°Hi RealFeel® 88° Precipitation 0%
    Mostly sunny and very warm
    • WSW 7 mph
    • Gusts: 14 mph
    • 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

    Night

    54°Lo RealFeel® 55° Precipitation 1%
    Mainly clear
    • W 5 mph
    • Gusts: 10 mph
    • 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

    more Historical Weather Data >
      Today Normal Record 9/27/2015
    High 87° 77° N/A 80°
    Low 54° 55° N/A 54°

    Sunrise/Sunset

    • Sunrise: 7:01 AM
    • Sunset: 6:56 PM
    • Duration: 11:55 hr

    Moonrise/Moonset

    • Moonrise: 3:49 AM
    • Moonset: 5:23 PM
    • Duration: 13:34 hr
    Astronomy

    Castro Valley Weather Report

    Northern California towns in danger of running out of water for 3rd year in a row

    September 25, 2016; 3:11 AM ET

    For the third year in a row, some communities in northern California may run out of water due to the extreme drought conditions gripping the state. More >

    Tue. Arthritis Pain

    Tue. UV Index