Current Conditions

Castro Valley, California

68°F20°C

Clear

Wind

W 7 mph12 km/h

Humidity

68%

Cloud Cover

18%

As of Thursday, July 23, 2026 at 10:03 AM PDT

Today's Outlook

Day

Partly cloudy and warm, with a high of 74°F23°C and morning low of 61°F16°C. Breezy from the W at 8 to 10 mph13 to 16 km/h.

Night

Partly cloudy, with a low around 58°F14°C. Breezy from the WSW at 6 to 7 mph9 to 12 km/h.

7-Day Forecast

Day	Condition	High (°F)	Low (°F)	Precip (mm)	Cloud Cover (%)	Wind (mph)
ThursdayJul 23	Clear	High 74°F23°C	Low 58°F14°C	Precip 0 in0 mm—	Cloud 28%	Wind W 7 mph12 km/h	Thursday: Partly cloudy and warm, with a high of 74°F23°C and morning low of 61°F16°C. Breezy from the W at 8 to 10 mph13 to 16 km/h. Thursday Night: Partly cloudy, with a low around 58°F14°C. Breezy from the WSW at 6 to 7 mph9 to 12 km/h.
FridayJul 24	Clear	High 75°F24°C	Low 57°F14°C	Precip 0 in0 mm—	Cloud 27%	Wind WSW 7 mph11 km/h	Friday: Mostly clear and warm, with a high of 75°F24°C and morning low of 60°F16°C. Breezy from the W at 8 to 10 mph14 to 17 km/h. Friday Night: Partly cloudy, with a low around 57°F14°C. Breezy from the WSW at 6 to 8 mph9 to 12 km/h.
SaturdayJul 25	Clear	High 76°F24°C	Low 57°F14°C	Precip 0 in0 mm—	Cloud 27%	Wind WSW 7 mph12 km/h	Saturday: Mostly clear and warm, with a high of 76°F24°C and morning low of 61°F16°C. Breezy from the W at 9 to 10 mph14 to 17 km/h. Saturday Night: Partly cloudy, with a low around 57°F14°C. Breezy from the WSW at 6 to 7 mph9 to 12 km/h.
SundayJul 26	Clear	High 74°F23°C	Low 58°F14°C	Precip 0 in0 mm—	Cloud 33%	Wind WSW 7 mph12 km/h	Sunday: Partly cloudy and warm, with a high of 74°F23°C and morning low of 61°F16°C. Breezy from the WSW at 9 to 10 mph14 to 16 km/h. Sunday Night: Partly cloudy, with a low around 58°F14°C. Breezy from the WSW at 6 to 8 mph10 to 13 km/h.
MondayJul 27	Clear	High 77°F25°C	Low 56°F14°C	Precip 0 in0 mm—	Cloud 24%	Wind WSW 6 mph10 km/h	Monday: Mostly clear and warm, with a high of 77°F25°C and morning low of 60°F16°C. Breezy from the WSW at 7 to 9 mph12 to 15 km/h. Monday Night: Partly cloudy, with a low around 56°F14°C. Light wind from the SW around 5 mph8 km/h.
TuesdayJul 28	Clear	High 78°F26°C	Low 58°F14°C	Precip 0 in0 mm—	Cloud 13%	Wind WSW 6 mph10 km/h	Tuesday: Mostly clear and warm, with a high of 78°F26°C and morning low of 62°F17°C. Breezy from the WSW at 7 to 9 mph12 to 15 km/h. Tuesday Night: Mostly clear, with a low around 58°F14°C. Light wind from the SW around 5 mph8 km/h.
WednesdayJul 29	Clear	High 79°F26°C	Low 59°F15°C	Precip 0 in0 mm—	Cloud 17%	Wind WSW 6 mph10 km/h	Wednesday: Mostly clear and warm, with a high of 79°F26°C and morning low of 62°F17°C. Breezy from the WSW at 7 to 9 mph11 to 15 km/h. Wednesday Night: Mostly clear, with a low around 59°F15°C. Light wind from the SW around 5 mph8 km/h.

15-Day Forecast

	Day	High (°F)	Low (°F)	Precip (mm)	Cloud Cover (%)	Condition	Wind (mph)
	ThursdayJul 23	74°F23°C	58°F14°C	0 in0 mm· —	28%	Clear	W 7 mph12 km/h
DayPartly cloudy and warm, with a high of 74°F23°C and morning low of 61°F16°C. Breezy from the W at 8 to 10 mph13 to 16 km/h. NightPartly cloudy, with a low around 58°F14°C. Breezy from the WSW at 6 to 7 mph9 to 12 km/h.
	FridayJul 24	75°F24°C	57°F14°C	0 in0 mm· —	27%	Clear	WSW 7 mph11 km/h
DayMostly clear and warm, with a high of 75°F24°C and morning low of 60°F16°C. Breezy from the W at 8 to 10 mph14 to 17 km/h. NightPartly cloudy, with a low around 57°F14°C. Breezy from the WSW at 6 to 8 mph9 to 12 km/h.
	SaturdayJul 25	76°F24°C	57°F14°C	0 in0 mm· —	27%	Clear	WSW 7 mph12 km/h
DayMostly clear and warm, with a high of 76°F24°C and morning low of 61°F16°C. Breezy from the W at 9 to 10 mph14 to 17 km/h. NightPartly cloudy, with a low around 57°F14°C. Breezy from the WSW at 6 to 7 mph9 to 12 km/h.
	SundayJul 26	74°F23°C	58°F14°C	0 in0 mm· —	33%	Clear	WSW 7 mph12 km/h
DayPartly cloudy and warm, with a high of 74°F23°C and morning low of 61°F16°C. Breezy from the WSW at 9 to 10 mph14 to 16 km/h. NightPartly cloudy, with a low around 58°F14°C. Breezy from the WSW at 6 to 8 mph10 to 13 km/h.
	MondayJul 27	77°F25°C	56°F14°C	0 in0 mm· —	24%	Clear	WSW 6 mph10 km/h
DayMostly clear and warm, with a high of 77°F25°C and morning low of 60°F16°C. Breezy from the WSW at 7 to 9 mph12 to 15 km/h. NightPartly cloudy, with a low around 56°F14°C. Light wind from the SW around 5 mph8 km/h.
	TuesdayJul 28	78°F26°C	58°F14°C	0 in0 mm· —	13%	Clear	WSW 6 mph10 km/h
DayMostly clear and warm, with a high of 78°F26°C and morning low of 62°F17°C. Breezy from the WSW at 7 to 9 mph12 to 15 km/h. NightMostly clear, with a low around 58°F14°C. Light wind from the SW around 5 mph8 km/h.
	WednesdayJul 29	79°F26°C	59°F15°C	0 in0 mm· —	17%	Clear	WSW 6 mph10 km/h
DayMostly clear and warm, with a high of 79°F26°C and morning low of 62°F17°C. Breezy from the WSW at 7 to 9 mph11 to 15 km/h. NightMostly clear, with a low around 59°F15°C. Light wind from the SW around 5 mph8 km/h.
	ThursdayJul 30	79°F26°C	58°F14°C	0 in0 mm· —	20%	Clear	WSW 6 mph10 km/h
DayMostly clear and warm, with a high of 79°F26°C and morning low of 62°F17°C. Breezy from the WSW at 7 to 9 mph11 to 14 km/h. NightMostly clear, with a low around 58°F14°C. Light wind from the SW around 5 mph8 km/h.
	FridayJul 31	81°F27°C	58°F14°C	0 in0 mm· —	21%	Clear	WSW 5 mph9 km/h
DayMostly clear and warm, with a high of 81°F27°C and morning low of 62°F16°C. Breezy from the WSW at 6 to 8 mph10 to 13 km/h. NightMostly clear, with a low around 58°F14°C. Light wind from the SW around 5 mph7 km/h.
	SaturdayAug 1	83°F29°C	59°F15°C	0 in0 mm· —	13%	Clear	SW 5 mph8 km/h
DayMostly clear and warm, with a high of 83°F29°C and morning low of 63°F17°C. Breezy from the WSW at 6 to 8 mph10 to 13 km/h. NightMostly clear, with a low around 59°F15°C. Light wind from the SW around 5 mph7 km/h.
	SundayAug 2	83°F28°C	59°F15°C	0 in0 mm· —	11%	Clear	SW 6 mph9 km/h
DayMostly clear and warm, with a high of 83°F28°C and morning low of 63°F17°C. Breezy from the WSW at 6 to 8 mph10 to 13 km/h. NightMostly clear, with a low around 59°F15°C. Light wind from the SW around 5 mph8 km/h.
	MondayAug 3	81°F27°C	60°F15°C	0 in0 mm· —	19%	Clear	SW 6 mph10 km/h
DayMostly clear and warm, with a high of 81°F27°C and morning low of 64°F18°C. Breezy from the WSW at 7 to 9 mph11 to 14 km/h. NightMostly clear, with a low around 60°F15°C. Breezy from the SW at 6 to 7 mph9 to 11 km/h.
	TuesdayAug 4	78°F26°C	59°F15°C	0 in0 mm· —	29%	Clear	SW 6 mph10 km/h
DayPartly cloudy and warm, with a high of 78°F26°C and morning low of 62°F17°C. Breezy from the WSW at 7 to 9 mph11 to 14 km/h. NightPartly cloudy, with a low around 59°F15°C. Breezy from the SW at 6 to 7 mph9 to 11 km/h.
	WednesdayAug 5	79°F26°C	59°F15°C	0 in0 mm· —	34%	Clear	WSW 6 mph10 km/h
DayPartly cloudy and warm, with a high of 79°F26°C and morning low of 63°F17°C. Breezy from the WSW at 7 to 9 mph11 to 14 km/h. NightPartly cloudy, with a low around 59°F15°C. Light wind from the SW around 5 mph9 km/h.
	ThursdayAug 6	79°F26°C	59°F15°C	0 in0 mm· —	37%	Clear	WSW 6 mph9 km/h
DayPartly cloudy and warm, with a high of 79°F26°C and morning low of 62°F17°C. Breezy from the WSW at 7 to 8 mph11 to 13 km/h. NightPartly cloudy, with a low around 59°F15°C. Light wind from the SW around 5 mph8 km/h.

Nearby Cities

Ashland2 mi2 km Hayward2 mi3 km San Lorenzo3 mi5 km San Leandro4 mi7 km Union City8 mi12 km Dublin8 mi13 km

About This Forecast

This forecast is powered by WeatherMesh, the world's most advanced and accurate weather model powered by AI. WeatherMesh is built on proprietary data from WindBorne's Global Sounding Balloon constellation — the world's largest fleet of autonomous, long-duration weather balloons — collecting observations across 100% of Earth, including over oceans and remote regions where no other data exists.

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Coordinates: 37.6941°N, 122.0863°W·Elevation: 50m·Timezone: America/Los_Angeles·Population: 61,388