10-Day Weather Forecast - Castro Valley, CA

Mostly cloudy. Highs in the 70s. Light winds. . . Becoming west 5 to 10 mph in the afternoon.

Mostly cloudy. A chance of rain after midnight. Lows in the mid 50s. West winds 5 to 10 mph.

Mostly cloudy. A chance of rain. Highs in the upper 60s. Southwest winds 5 to 10 mph. Chance of rain 40 percent.

Mostly cloudy. A chance of rain. Lows in the lower 50s. Southwest winds 5 to 10 mph. Chance of rain 40 percent.

Mostly cloudy. A chance of rain. Highs in the upper 60s.

Mostly cloudy. A chance of rain. Lows around 50.

Mostly cloudy in the morning then becoming sunny. A chance of rain. Highs in the mid 60s.

Clear. Lows in the 40s to lower 50s. Highs in the 70s to lower 80s.

Clear. Lows in the 40s to lower 50s. Highs in the 70s to lower 80s.

Clear. Lows in the 40s to lower 50s. Highs in the 70s to lower 80s.

Clear. Lows in the 40s to lower 50s. Highs in the 70s to lower 80s.

Clear. Lows in the 40s to lower 50s. Highs in the 70s to lower 80s.

Sunny. Highs in the mid 70s to lower 80s.

Clear. Low temperature around 50F. Dew point will be around 46F with an average humidity of 68%. Winds will be 5 mph from the W.

Sunny. High temperature around 73F. Dew point will be around 48F with an average humidity of 54%. Winds will be 6 mph from the W.

Clear. Low temperature around 48F. Dew point will be around 47F with an average humidity of 77%. Winds will be 6 mph from the W.

Sunny. High temperature around 70F. Dew point will be around 48F with an average humidity of 59%. Winds will be 7 mph from the W.

Clear. Low temperature around 47F. Dew point will be around 46F with an average humidity of 78%. Winds will be 6 mph from the W.