August weather forecast
Castro Valley, CA

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Weather in August

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

Temperature

Stepping into August, Castro Valley records an average high-temperature of a still warm 79.7°F (26.5°C), almost consistent with July. From the heights of the August heat, Castro Valley records a mean nighttime low of 56.5°F (13.6°C).

Humidity

In August, the average relative humidity in Castro Valley, California, is 65%.

Rainfall

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

Daylight

In August, the average length of the day is 13h and 34min.
On the first day of the month, sunrise is at 6:12 am and sunset at 8:16 pm. On the last day of August, sunrise is at 6:38 am and sunset at 7:38 pm PDT.

Sunshine

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

UV index

The average daily maximum UV index in August in Castro Valley is 5. A UV Index estimate of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for average individuals.
Note: In August, an average UV index of 5 transforms into the following instructions:
Take measures. Individuals with light skin might experience burns in under 30 minutes. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. Opt for tightly woven and loose clothing to enhance protection from the Sun.
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Frequently asked questions

What is the temperature in August in Castro Valley?

In August, the average high-temperature and low-temperature in Castro Valley are 79.7°F (26.5°C) and 56.5°F (13.6°C) respectively.

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 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, during August, the rain falls for 0.9 days and regularly aggregates up to 0.04" (1mm) of precipitation.

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

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

When are sunrise and sunset in August in Castro Valley?

In August, on the first day of the month, sunrise is at 6:12 am and sunset at 8:16 pm. On the last day of the month, in Castro Valley, sunrise is at 6:38 am and sunset at 7:38 pm PDT.

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

In August, the average sunshine duration is 12h.

What is the UV index reading in August in Castro Valley?

In Castro Valley, the average daily maximum UV index in August is 5. A UV Index value of 3 to 5 symbolizes a moderate vulnerability from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average daylight
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 4min

The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).

  • 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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Castro Valley, California, USA

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