August weather forecast
Sonoma, CA

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Neat rows of vines in a vineyard farm in Sonoma, California
Neat rows of vines in a vineyard farm in Sonoma, California

Weather in August

In August, Sonoma's weather remains consistently hot and dry, mirroring the conditions of July. Aside from a tiny increase in temperature, the weather patterns persist with blazing sun, minimal rainfall, and clear skies. Increased sunshine hours and reduced cloud cover emphasize how firmly August is embedded in the summer season. Nevertheless, the month sees a very slight uptick in relative humidity and cloud cover towards the end, alluding to the incoming seasonal shift.

Temperature

The month of August sees the highest average temperatures, reaching 82.9°F (28.3°C) at the peak and 54.9°F (12.7°C) at the low.

Heat index

In August, the heat index is appraised at a tropical 86°F (30°C). Ongoing exposure and activity could lead to a state of exhaustion, with a chance of heat cramps.
Evaluating the heat index requires understanding its values in the shade and with gentle winds. An exposure to direct sunlight may lift the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', takes into account both air temperature and humidity to illustrate what people actually feel. The individual's temperature perception can be influenced by numerous factors such as metabolic variations, physical activity, and clothing. In direct sunlight, the heat's impact can be heightened, potentially leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are of high significance for children. Youths are typically more endangered than adults since they usually sweat less. Their larger skin surface concerning their smaller bodies and higher heat production due to activity further adds to their vulnerability.

Humidity

The average relative humidity in August is 64%.

Rainfall

The months with the least rainfall are July and August Rain falls for 0.8 days and accumulates 0.04" (1mm) of rain.

Daylight

In August, the average length of the day is 13h and 36min.
On the first day of August, sunrise is at 6:12 am and sunset at 8:19 pm. On the last day of the month, sunrise is at 6:39 am and sunset at 7:40 pm PDT.

Sunshine

In August, the average sunshine is 11.9h.

UV index

The average daily maximum UV index in August is 5. A UV Index of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for average individuals.
Note: A maximum UV index of 5 in August translates into the following recommendations:
Exercise care. People with light skin might get burns in fewer than 30 minutes. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays.
Updated: Jul 17, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What part of the year is the hottest?

August is the month that records the highest temperatures, with averages ranging from a high of 82.9°F (28.3°C) to a low of 54.9°F (12.7°C).

Is it hot during August?

August temperatures vary between a high-temperature of 82.9°F (28.3°C) and a low-temperature of 54.9°F (12.7°C). The average heat index (a.k.a. 'apparent temperature', 'feels like'), which takes the relative humidity and factors it into the air temperature reading, in August is appraised at 86°F (30°C).

What is the average humidity in August?

In Sonoma, the average relative humidity in August is 64%.

What is the driest month?

July and August are months with the least rain when the rain falls for 0.8 days and typically aggregates up to 0.04" (1mm) of rain.

How many days does it rain in August?

In Sonoma, in August, during 0.8 rainfall days, 0.04" (1mm) of precipitation is typically accumulated.

How many hours of daylight does Sonoma have in August?

In August, the average day length is 13h and 36min.

What time are sunrise and sunset in August?

On the first day of August, sunrise is at 6:12 am and sunset at 8:19 pm. On the last day of the month, sunrise is at 6:39 am and sunset at 7:40 pm PDT.

How many hours of sunshine does Sonoma have in August?

In Sonoma, California, the average sunshine duration in August is 11.9h.

How high is the UV index in August?

In Sonoma, the average daily maximum UV index in August is 5. A UV Index estimate of 3 to 5 represents a medium health risk from 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
Sonoma, CA

Average temperature in August - Sonoma, CA
  • Average high temperature in August: 82.9°F

The warmest month (with the highest average high temperature) is August (82.9°F).
The month with the lowest average high temperature is December (55°F).

  • Average low temperature in August: 54.9°F

The month with the highest average low temperature is August (54.9°F).
The coldest month (with the lowest average low temperature) is December (41.4°F).

Average pressure in August
Sonoma, CA

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

The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

Average wind speed in August
Sonoma, CA

Average wind speed in August - Sonoma, CA
  • Average wind speed in August: 5mph

The windiest month (with the highest average wind speed) is May (6.2mph).
The calmest month (with the lowest average wind speed) is November (4.4mph).

Average humidity in August
Sonoma, CA

Average humidity in August - Sonoma, CA
  • Average humidity in August: 64%

The month with the highest relative humidity is March (76%).
The month with the lowest relative humidity is September (59%).

Average rainfall in August
Sonoma, CA

Average rainfall in August - Sonoma, CA
  • Average rainfall in August: 0.04"

The wettest month (with the highest rainfall) is February (3.43").
The driest months (with the least rainfall) are July and August (0.04").

Average rainfall days in August
Sonoma, CA

Average rainfall days in August - Sonoma, CA
  • Average rainfall days in August: 0.8 days

The month with the highest number of rainy days is March (13.4 days).
The month with the least rainy days is August (0.8 days).

Average daylight in August /
Average sunshine in August
Sonoma, CA

Average daylight in August / Average sunshine in August - Sonoma, CA
  • Average daylight in August: 13h and 4min

The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 36min).

  • Average sunshine in August: 11h and 5min

The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 36min).

Average sunshine days in August
Sonoma, CA

Average sunshine days in August - Sonoma, CA
  • Average sunshine days in August: 28.3 days

The month with the most sunshine days is July (28.7 days).
The month with the least sunshine days is March (16.1 days).

Average UV index in August
Sonoma, CA

Average UV index in August - Sonoma, CA
  • Average UV index in August: 5

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

Average cloud cover in August
Sonoma, CA

Average cloud cover in August - Sonoma, CA
  • Average cloud cover in August: 9

The month with the most cloud cover is March (Cloud cover 40).
The month with the least cloud cover is July (Cloud cover 8).

Average visibility in August
Sonoma, CA

Average visibility in August - Sonoma, 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).

Sonoma, California, USA

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