10-Day Weather Forecast - Castro Valley, CA

Sunny. Highs in the 70s to lower 80s. Light winds. . . Becoming northwest around 5 mph in the afternoon.

Mostly clear except patchy fog after midnight. Lows in the lower 50s. West winds up to 5 mph.

Partly cloudy in the morning then becoming sunny. Areas of fog in the morning. Highs in the mid 60s to lower 70s. Northwest winds around 5 mph increasing to west 10 to 20 mph in the afternoon.

Mostly clear in the evening then becoming mostly cloudy. Lows in the upper 40s.

Mostly cloudy. Highs in the mid 60s to lower 70s.

Mostly cloudy in the evening then becoming mostly clear. Lows in the upper 40s.

Clear. Highs in the upper 60s to mid 70s. Lows in the lower 50s.

Clear. Highs in the upper 60s to mid 70s. Lows in the lower 50s.

Mostly clear. Highs in the 70s. Lows in the lower 50s.

Mostly clear. Highs in the 70s. Lows in the lower 50s.

Mostly clear. Highs in the 70s. Lows in the lower 50s.

Mostly clear. Low temperature around 49F. Dew point will be around 48F with an average humidity of 72%. Winds will be 5 mph from the W.

Mostly sunny. High temperature around 71F. Dew point will be around 46F with an average humidity of 55%. Winds will be 6 mph from the W.

Mostly clear. Low temperature around 49F. Dew point will be around 47F with an average humidity of 78%. Winds will be 5 mph from the W.

Mostly sunny. High temperature around 71F. Dew point will be around 48F with an average humidity of 54%. Winds will be 6 mph from the NW.

Mostly clear. Low temperature around 50F. Dew point will be around 46F with an average humidity of 70%. Winds will be 3 mph from the W.

Partly cloudy. High temperature around 74F. Dew point will be around 46F with an average humidity of 46%. Winds will be 4 mph from the NW.

Partly cloudy. Low temperature around 52F. Dew point will be around 46F with an average humidity of 66%. Winds will be 3 mph from the W.