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Personalized Forecasts

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    My Recent Locations

    • Today

      Sep 30

      65° /52°F
      Low clouds, then sun
      • Lawn Mowing
        • Lawn Mowing
        • Soil Moisture
        • Field Readiness
        • Composting
      • Excellent
      • for lawn mowing
      • Hours of Precip: 0
      • Precip: 4%
      • Hi RealFeel: 65°
    • Sat

      Oct 1

      69° /54°
      Low clouds, then sun and cool
      • Excellent
      • for lawn mowing
      • Hours of Precip: 0
      • Precip: 9%
      • Hi RealFeel: 71°
      More
    • Sun

      Oct 2

      65° /51°
      A p.m. shower in places
      • Very Good
      • for lawn mowing
      • Hours of Precip: 2
      • Precip: 54%
      • Hi RealFeel: 64°
      More
    • Mon

      Oct 3

      65° /55°
      Partly sunny and cool
      • Excellent
      • for lawn mowing
      • Hours of Precip: 0
      • Precip: 9%
      • Hi RealFeel: 69°
      More
    • Tue

      Oct 4

      69° /50°
      Sun and some clouds
      • Excellent
      • for lawn mowing
      • Hours of Precip: 0
      • Precip: 3%
      • Hi RealFeel: 71°
      More

    Day

    65°Hi RealFeel® 65° Precipitation 4%
    Low clouds followed by sunshine
    • W 13 mph
    • Gusts: 21 mph
    • Max UV Index: 5 (Moderate)
    • Thunderstorms: 7%
    • Precipitation: 0 in
    • Rain: 0 in
    • Snow: 0 in
    • Ice: 0 in
    • Hours of Precipitation: 0 hrs
    • Hours of Rain: 0 hrs

    Night

    52°Lo RealFeel® 51° Precipitation 8%
    Mainly clear this evening followed by low clouds late
    • W 7 mph
    • Gusts: 15 mph
    • 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

    more Historical Weather Data >
      Today Normal Record 9/30/2015
    High 65° 77° N/A 65°
    Low 52° 55° N/A 56°

    Sunrise/Sunset

    • Sunrise: 7:04 AM
    • Sunset: 6:52 PM
    • Duration: 11:48 hr

    Moonrise/Moonset

    • Moonrise: 6:42 AM
    • Moonset: 6:59 PM
    • Duration: 12:17 hr
    Astronomy

    Castro Valley Weather Report

    Cooler air, showers to aid in wildfire efforts across California this weekend

    September 30, 2016; 9:54 AM ET

    Improving weather over the next several days will aid officials in battling wildfires across California. More >

    Current Drought Status

    Current Soil Conditions

    Fri. Overnight Freeze

    Fri. Degree Days

    Fri. Evapotranspiration