August weather forecast
Castro Valley, CA

Weather in August

August, the last month of the summer in Castro Valley, is another warm month, with an average temperature fluctuating between 56.5°F (13.6°C) and 79.7°F (26.5°C).

Temperature

In August, the average high-temperature is practically the same as in July - a still warm 79.7°F (26.5°C). In Castro Valley, California, in August, the average low-temperature is 56.5°F (13.6°C).

Humidity

The average relative humidity in August in Castro Valley is 65%.

Rainfall

The months with the least rainfall are July and August Rain falls for 0.9 days and accumulates 0.04" (1mm) of rain.

Daylight

In Castro Valley, the average length of the day in August is 13h and 34min.
On the first day of August in Castro Valley, California, sunrise is at 6:12 am and sunset at 8:17 pm. On the last day of the month, sunrise is at 6:37 am and sunset at 7:39 pm PDT.

Sunshine

In Castro Valley, the average sunshine in August is 12h.

UV index

In August, the average daily maximum UV index in Castro Valley is 5. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for the ordinary person.
Note: The daily maximum UV index of 5 in August interpret into the following advice:
Take precautions. Light skin individuals may get burned in less than 30 minutes. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
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FAQ

What is the temperature in August in Castro Valley?

The average high-temperature, in August, is 79.7°F (26.5°C), while the average low-temperature is 56.5°F (13.6°C).

What is the average humidity in August in Castro Valley?

The average relative humidity in August is 65%.

What is the driest month in Castro Valley?

July and August are months with the least rain in Castro Valley, California, when the rain falls for 0.9 days and typically aggregates up to 0.04" (1mm) of rain.

How many days does it rain in August in Castro Valley?

In Castro Valley, in August, during 0.9 rainfall days, 0.04" (1mm) of precipitation is typically accumulated.

How many hours of daylight does Castro Valley have in August?

In August, the average day length is 13h and 34min.

When is the sunrise / sunset in August in Castro Valley?

On the first day of August in Castro Valley, sunrise is at 6:12 am and sunset at 8:17 pm. On the last day of the month, sunrise is at 6:37 am and sunset at 7:39 pm PDT.

How long on average sun shines in August in Castro Valley?

The average sunshine duration in August in Castro Valley, California, is 12h.

How high is the UV index in August in Castro Valley?

The average daily maximum UV index in August in Castro Valley is 5. A UV Index reading of 3 to 5 represents a moderate vulnerability from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in August
Castro Valley, CA

Average temperature in August - Castro Valley, CA
  • Average high temperature in August: 79.7°F

The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is December (55.9°F).

  • Average low temperature in August: 56.5°F

The month with the highest average low temperature is August (56.5°F).
The coldest months (with the lowest average low temperature) are January and December (43.7°F).

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Average pressure in August
Castro Valley, CA

Average pressure in August - Castro Valley, CA
  • Average pressure in August: 29.92"Hg

The month with the highest atmospheric pressure is January (30.14"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).

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Average wind speed in August
Castro Valley, CA

Average wind speed in August - Castro Valley, CA
  • Average wind speed in August: 5.4mph

The windiest month (with the highest average wind speed) is May (6.6mph).
The calmest month (with the lowest average wind speed) is November (4.6mph).

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Average humidity in August
Castro Valley, CA

Average humidity in August - Castro Valley, CA
  • Average humidity in August: 65%

The month with the highest relative humidity is March (74%).
The month with the lowest relative humidity is September (61%).

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Average rainfall in August
Castro Valley, CA

Average rainfall in August - Castro Valley, CA
  • Average rainfall in August: 0.04"

The wettest month (with the highest rainfall) is February (2.28").
The driest months (with the least rainfall) are July and August (0.04").

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Average rainfall days in August
Castro Valley, CA

Average rainfall days in August - Castro Valley, CA
  • Average rainfall days in August: 0.9 days

The month with the highest number of rainy days is March (12.4 days).
The month with the least rainy days is August (0.9 days).

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Average daylight in August /
Average sunshine in August
Castro Valley, CA

Average daylight in August / Average sunshine in August - Castro Valley, CA
  • Average daylight in August: 13h and 34min

The month with the longest days is June (Average daylight: 14h and 44min).
The month with the shortest days is December (Average daylight: 9h and 37min).

  • Average sunshine in August: 12h and 0min

The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 54min).

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Average sunshine days in August
Castro Valley, CA

Average sunshine days in August - Castro Valley, CA
  • Average sunshine days in August: 28.9 days

The month with the most sunshine days is August (28.9 days).
The month with the least sunshine days is March (17.3 days).

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Average UV index in August
Castro Valley, CA

Average UV index in August - Castro Valley, CA
  • Average UV index in August: 5

The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).

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Average cloud cover in August
Castro Valley, CA

Average cloud cover in August - Castro Valley, CA
  • Average cloud cover in August: 8

The months with the most cloud cover are March and December (Cloud cover 34).
The month with the least cloud cover is July (Cloud cover 7).

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Average visibility in August
Castro Valley, CA

Average visibility in August - Castro Valley, CA
  • Average visibility in August: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

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