What is the weather in Castro Valley right now?

Current weather in Castro Valley is overcast clouds.

Where can I find the hourly weather forecast for Castro Valley?

This page shows hourly weather forecast for Castro Valley, including temperature, wind, precipitation, humidity and cloud cover.

Is the weather forecast for Castro Valley updated regularly?

Weather data for Castro Valley is updated regularly with the latest available observations and forecasts.

Now · 7:26 AM

Castro Valley Weather & Hourly Forecast

United States · California · 94552

63°F

Overcast

Feels like: 63°F

💧 Humidity 72% 🌡 Pressure 29.94 inHg 💨 Wind 4 mph 👁 Visibility 6.2 mi ☁ Clouds 100% ☀️ UV index 4.0 · Moderate 🌅 Sunrise 6:35 AM 🌇 Sunset 7:44 PM

Hourly Forecast for Castro Valley

Today

8:00 AM

Overcast

63° 💧 None 💨 4 mph H 72%29.94 inHg

11:00 AM

Overcast

65° 💧 None 💨 5 mph H 68%30.00 inHg

2:00 PM

Overcast

75° 💧 None 💨 2 mph H 35%29.97 inHg

5:00 PM

Mostly cloudy

77° 💧 None 💨 9 mph H 35%29.94 inHg

8:00 PM

Clear night

69° 💧 None 💨 5 mph H 62%29.94 inHg

11:00 PM

Clear night

63° 💧 None 💨 3 mph H 74%29.97 inHg

Tomorrow

2:00 AM

Clear night

59° 💧 None 💨 3 mph H 79%29.94 inHg

5:00 AM

Clear night

56° 💧 None 💨 2 mph H 88%29.94 inHg

8:00 AM

Sunny

61° 💧 None 💨 2 mph H 77%29.97 inHg

11:00 AM

Sunny

74° 💧 None 💨 3 mph H 42%29.97 inHg

2:00 PM

Sunny

80° 💧 None 💨 7 mph H 36%29.94 inHg

5:00 PM

Sunny

74° 💧 None 💨 7 mph H 48%29.91 inHg

8:00 PM

Clear night

62° 💧 None 💨 7 mph H 76%29.94 inHg

11:00 PM

Clear night

58° 💧 None 💨 8 mph H 84%29.94 inHg

Sunday

2:00 AM

Mostly clear night

57° 💧 None 💨 6 mph H 88%29.91 inHg

5:00 AM

Partly cloudy night

57° 💧 None 💨 6 mph H 85%29.91 inHg

Today

8:00 AM

Overcast

63° 💧 None 💨 4 mph H 72%29.94 inHg

9:00 AM

Overcast

64° 💧 None 💨 3 mph H 72%29.94 inHg

10:00 AM

Overcast

64° 💧 None 💨 4 mph H 69%29.97 inHg

11:00 AM

Overcast

65° 💧 None 💨 5 mph H 68%30.00 inHg

12:00 PM

Overcast

66° 💧 None 💨 0 mph H 69%30.03 inHg

1:00 PM

Overcast

70° 💧 None 💨 1 mph H 48%30.00 inHg

2:00 PM

Overcast

75° 💧 None 💨 2 mph H 35%29.97 inHg

3:00 PM

Overcast

79° 💧 None 💨 7 mph H 30%29.97 inHg

4:00 PM

Mostly cloudy

79° 💧 None 💨 8 mph H 33%29.94 inHg

5:00 PM

Mostly cloudy

77° 💧 None 💨 9 mph H 35%29.94 inHg

6:00 PM

Sunny

75° 💧 None 💨 8 mph H 40%29.94 inHg

7:00 PM

Sunny

73° 💧 None 💨 6 mph H 49%29.94 inHg

8:00 PM

Clear night

69° 💧 None 💨 5 mph H 62%29.94 inHg

9:00 PM

Clear night

66° 💧 None 💨 4 mph H 68%29.97 inHg

10:00 PM

Clear night

65° 💧 None 💨 3 mph H 71%29.97 inHg

11:00 PM

Clear night

63° 💧 None 💨 3 mph H 74%29.97 inHg

Tomorrow

12:00 AM

Clear night

62° 💧 None 💨 3 mph H 76%29.97 inHg

1:00 AM

Clear night

61° 💧 None 💨 3 mph H 78%29.97 inHg

2:00 AM

Clear night

59° 💧 None 💨 3 mph H 79%29.94 inHg

3:00 AM

Clear night

58° 💧 None 💨 3 mph H 82%29.94 inHg

4:00 AM

Clear night

57° 💧 None 💨 2 mph H 86%29.94 inHg

5:00 AM

Clear night

56° 💧 None 💨 2 mph H 88%29.94 inHg

6:00 AM

Clear night

55° 💧 None 💨 2 mph H 90%29.97 inHg

7:00 AM

Sunny

56° 💧 None 💨 2 mph H 90%29.97 inHg

8:00 AM

Sunny

61° 💧 None 💨 2 mph H 77%29.97 inHg

9:00 AM

Sunny

66° 💧 None 💨 3 mph H 63%29.97 inHg

10:00 AM

Sunny

69° 💧 None 💨 3 mph H 51%29.97 inHg

11:00 AM

Sunny

74° 💧 None 💨 3 mph H 42%29.97 inHg

12:00 PM

Sunny

76° 💧 None 💨 5 mph H 37%29.97 inHg

1:00 PM

Sunny

78° 💧 None 💨 6 mph H 36%29.94 inHg

2:00 PM

Sunny

80° 💧 None 💨 7 mph H 36%29.94 inHg

3:00 PM

Sunny

80° 💧 None 💨 8 mph H 38%29.91 inHg

4:00 PM

Sunny

78° 💧 None 💨 9 mph H 43%29.91 inHg

5:00 PM

Sunny

74° 💧 None 💨 7 mph H 48%29.91 inHg

6:00 PM

Sunny

70° 💧 None 💨 8 mph H 54%29.91 inHg

7:00 PM

Sunny

66° 💧 None 💨 8 mph H 64%29.94 inHg

8:00 PM

Clear night

62° 💧 None 💨 7 mph H 76%29.94 inHg

9:00 PM

Clear night

60° 💧 None 💨 7 mph H 81%29.94 inHg

10:00 PM

Clear night

58° 💧 None 💨 7 mph H 82%29.94 inHg

11:00 PM

Clear night

58° 💧 None 💨 8 mph H 84%29.94 inHg

Sunday

12:00 AM

Clear night

58° 💧 None 💨 7 mph H 85%29.91 inHg

1:00 AM

Clear night

57° 💧 None 💨 7 mph H 87%29.94 inHg

2:00 AM

Mostly clear night

57° 💧 None 💨 6 mph H 88%29.91 inHg

3:00 AM

Mostly clear night

57° 💧 None 💨 6 mph H 87%29.91 inHg

4:00 AM

Mostly clear night

57° 💧 None 💨 6 mph H 87%29.91 inHg

5:00 AM

Partly cloudy night

57° 💧 None 💨 6 mph H 85%29.91 inHg

6:00 AM

Mostly cloudy night

57° 💧 None 💨 6 mph H 84%29.91 inHg

7:00 AM

Mostly cloudy

57° 💧 None 💨 5 mph H 83%29.94 inHg

8:00 AM

Partly cloudy

59° 💧 None 💨 4 mph H 77%29.94 inHg

9:00 AM

Partly cloudy

62° 💧 None 💨 4 mph H 68%29.94 inHg

10:00 AM

Partly cloudy

66° 💧 None 💨 4 mph H 57%29.94 inHg

11:00 AM

Partly cloudy

71° 💧 None 💨 4 mph H 49%29.94 inHg

12:00 PM

Sunny

74° 💧 None 💨 5 mph H 43%29.91 inHg

1:00 PM

Sunny

76° 💧 None 💨 6 mph H 39%29.91 inHg

2:00 PM

Sunny

77° 💧 None 💨 7 mph H 38%29.88 inHg

3:00 PM

Sunny

77° 💧 None 💨 7 mph H 40%29.85 inHg

4:00 PM

Sunny

76° 💧 None 💨 7 mph H 41%29.85 inHg

5:00 PM

Sunny

74° 💧 None 💨 7 mph H 44%29.85 inHg

6:00 PM

Sunny

71° 💧 None 💨 7 mph H 49%29.85 inHg

7:00 PM

Sunny

66° 💧 None 💨 6 mph H 57%29.85 inHg

8:00 PM

Clear night

60° 💧 None 💨 5 mph H 74%29.85 inHg

9:00 PM

Clear night

59° 💧 None 💨 4 mph H 82%29.88 inHg

10:00 PM

Clear night

58° 💧 None 💨 4 mph H 84%29.88 inHg

11:00 PM

Clear night

57° 💧 None 💨 3 mph H 86%29.88 inHg

Monday

12:00 AM

Clear night

57° 💧 None 💨 3 mph H 87%29.85 inHg

1:00 AM

Clear night

56° 💧 None 💨 3 mph H 88%29.85 inHg

2:00 AM

Clear night

56° 💧 None 💨 3 mph H 90%29.85 inHg

3:00 AM

Clear night

55° 💧 None 💨 3 mph H 91%29.85 inHg

4:00 AM

Clear night

56° 💧 None 💨 3 mph H 89%29.85 inHg

5:00 AM

Clear night

56° 💧 None 💨 3 mph H 90%29.85 inHg

6:00 AM

Partly cloudy night

56° 💧 None 💨 3 mph H 89%29.85 inHg

7:00 AM

Partly cloudy

55° 💧 None 💨 3 mph H 89%29.88 inHg

8:00 AM

Partly cloudy

59° 💧 None 💨 3 mph H 80%29.88 inHg

9:00 AM

Partly cloudy

62° 💧 None 💨 3 mph H 70%29.88 inHg

10:00 AM

Partly cloudy

65° 💧 None 💨 5 mph H 62%29.88 inHg

11:00 AM

Mostly sunny

68° 💧 None 💨 5 mph H 56%29.91 inHg

12:00 PM

Sunny

70° 💧 None 💨 7 mph H 53%29.91 inHg

1:00 PM

Sunny

72° 💧 None 💨 8 mph H 50%29.88 inHg

2:00 PM

Sunny

73° 💧 None 💨 9 mph H 48%29.88 inHg

3:00 PM

Sunny

72° 💧 None 💨 11 mph H 49%29.85 inHg

4:00 PM

Sunny

71° 💧 None 💨 11 mph H 52%29.85 inHg

5:00 PM

Sunny

69° 💧 None 💨 11 mph H 57%29.85 inHg

6:00 PM

Sunny

66° 💧 None 💨 11 mph H 63%29.85 inHg

7:00 PM

Sunny

64° 💧 None 💨 9 mph H 70%29.85 inHg

8:00 PM

Clear night

61° 💧 None 💨 7 mph H 80%29.88 inHg

9:00 PM

Clear night

61° 💧 None 💨 6 mph H 81%29.88 inHg

10:00 PM

Mostly clear night

61° 💧 None 💨 6 mph H 81%29.88 inHg

11:00 PM

Partly cloudy night

60° 💧 None 💨 6 mph H 81%29.88 inHg

Tuesday

12:00 AM

Mostly cloudy night

60° 💧 None 💨 6 mph H 82%29.88 inHg

1:00 AM

Mostly cloudy night

60° 💧 None 💨 5 mph H 80%29.88 inHg

2:00 AM

Mostly cloudy night

60° 💧 None 💨 5 mph H 79%29.88 inHg

3:00 AM

Mostly cloudy night

61° 💧 None 💨 5 mph H 76%29.88 inHg

4:00 AM

Mostly cloudy night

61° 💧 None 💨 5 mph H 75%29.88 inHg

5:00 AM

Mostly cloudy night

61° 💧 None 💨 5 mph H 76%29.91 inHg

6:00 AM

Overcast night

60° 💧 None 💨 5 mph H 76%29.91 inHg

7:00 AM

Overcast

60° 💧 None 💨 5 mph H 76%29.94 inHg

In Castro Valley and, more broadly, across the state of California: This morning will start with mostly cloudy skies and temperatures ranging from the mid-70s to low 80s. Winds from the northwest will be moderate, with speeds up to 16 mph and gusts reaching 23 mph. As the day progresses, the cloud cover will persist, but no rain is expected. Temperatures are likely to rise slightly, reaching into the low to mid-80s by afternoon. Winds will continue from the northwest, maintaining moderate speeds. Overall, it will be a mild to warm day with mostly cloudy conditions and steady breezes.

15-Day Weather Outlook for Castro Valley

TomorrowTomorrow

Sunny 80°/55° 💧 None 💨 9 mph

Sunday, Aug 30Sun Aug 30

Sunny 77°/57° 💧 None 💨 7 mph

Monday, Aug 31Mon Aug 31

Sunny 73°/55° 💧 None 💨 11 mph

Tuesday, Sep 1Tue Sep 1

Sunny 71°/59° 💧 None 💨 11 mph

Wednesday, Sep 2Wed Sep 2

Mostly sunny 72°/58° 💧 None 💨 9 mph

Thursday, Sep 3Thu Sep 3

Sunny 73°/56° 💧 None 💨 13 mph

Friday, Sep 4Fri Sep 4

Sunny 73°/56° 💧 None 💨 11 mph

Saturday, Sep 5Sat Sep 5

Sunny 71°/54° 💧 None 💨 11 mph

Sunday, Sep 6Sun Sep 6

Sunny 72°/53° 💧 None 💨 10 mph

Monday, Sep 7Mon Sep 7

Sunny 74°/53° 💧 None 💨 8 mph

Tuesday, Sep 8Tue Sep 8

Mostly sunny 78°/53° 💧 None 💨 7 mph

Wednesday, Sep 9Wed Sep 9

Overcast 82°/55° 💧 None 💨 7 mph

Thursday, Sep 10Thu Sep 10

Sunny 81°/55° 💧 None 💨 8 mph

Friday, Sep 11Fri Sep 11

Sunny 85°/56° 💧 None 💨 7 mph

Saturday, Sep 12Sat Sep 12

Overcast 84°/58° 💧 None 💨 7 mph

TEMPERATURE OUTLOOK

Temperature & Weather Trends in Castro Valley

Vertical axis: °F · Color based on temperature

AIR QUALITY FORECAST

Air Quality Forecast for Castro Valley

Hourly forecast · Updated every 2 hours

Good

Nearest forecast value 8:00 AM

PM2.5 Fine particles Good 3,1µg/m³

Microscopic particles that can penetrate deep into the lungs. Elevated concentrations can especially affect children, older adults and people with respiratory conditions.

PM10 Particulate matter Good 10,5µg/m³

Includes dust, pollen and other airborne particles. High concentrations may irritate the respiratory system.

O₃ Ozone Good 52,9µg/m³

Ground-level ozone can irritate the eyes and respiratory system when concentrations are elevated.

NO₂ Nitrogen dioxide Good 1,3µg/m³

A gas emitted mainly by traffic and some industrial activity. High exposure can affect respiratory health.

Air quality is favorable for outdoor activities.

UV & HEALTH

UV, Sun & Health Outlook in Castro Valley

Maximum daily UV Today, tomorrow and the following day show the maximum UV index forecast for each day.

0–2 Low 3–5 Moderate 6–7 High 8–10 Very high 11+ Extreme

Today UV 7,0High 😊Good

Tomorrow UV 7,0High 🙂Fair

Sunday UV 6,0High 🙂Fair

Monday UV 6,0High 🙂Fair

Tuesday UV 6,0High 😐Moderate

Wednesday UV 6,0High —Unavailable

Thursday UV 6,0High —Unavailable

Hourly UV index today

8:00 AMUV 4,0 9:00 AMUV 4,0 10:00 AMUV 4,0 11:00 AMUV 4,0 12:00 PMUV 4,0 1:00 PMUV 5,0 2:00 PMUV 5,0 3:00 PMUV 7,0 4:00 PMUV 7,0 5:00 PMUV 7,0 6:00 PMUV 7,0 7:00 PMUV 6,0

Today's weather health advice Open today's recommendations.

Strong UV exposure

Protect exposed skin with SPF 30+ sunscreen, wear sunglasses, and try to limit direct midday sun.

Good air quality

Air quality is good and outdoor activities can be enjoyed normally.

Comfortable temperature conditions

Temperatures should feel comfortable for most people, with no particular heat or cold precautions needed.

Good conditions for outdoor activities

Outdoor activities can generally be enjoyed normally, with sun protection adjusted to the UV level.

WIND OUTLOOK

Hourly Wind Forecast for Castro Valley

Vertical axis: mph · Horizontal axis: hours

Sustained wind Max gusts

Internal PR simulation: 4.63 Population: 65,001

DISCOVER WEATHER NEARBY Weather in other cities

Explore current conditions and forecasts for other locations.

Country Squire Lakes US · Indiana · 3,057 residents Upland US · Pennsylvania · 3,057 residents Little Flock US · Arkansas · 3,056 residents Cliffwood Beach US · New Jersey · 3,056 residents San Saba US · Texas · 3,056 residents Charnwood AU · Australian Capital Territory · 3,055 residents Crumbles GB · England · 3,055 residents Newton and Blackwell GB · England · 3,055 residents Bal Harbour US · Florida · 3,055 residents Saluda US · South Carolina · 3,055 residents Page AU · Australian Capital Territory · 3,054 residents Garden Hill First Nation CA · Manitoba · 3,054 residents Yowie Bay AU · New South Wales · 3,053 residents Moulden AU · Northern Territory · 3,053 residents Peguis 1B CA · Manitoba · 3,053 residents Saint-André-d'Argenteuil CA · Quebec · 3,053 residents

Forecast data for Castro Valley were last refreshed today at 7:26 AM. The current forecast period extends through 30/08/2026 at 5:00 AM. Weather, air-quality and UV-index data are provided through WEATHER-INFO.COM. Forecasts are produced automatically from the latest available data and are subject to periodic technical checks. This service is intended for general weather information.