August weather forecast
Simi Valley, CA

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The Simi Valley city in California, with a view of the scenic Rocky Peak and hilly ranges
The Simi Valley city in California, with a view of the scenic Rocky Peak and hilly ranges

Weather in August

August, the last month of the summer in Simi Valley, is another warm month, with an average temperature fluctuating between 82.2°F (27.9°C) and 63.1°F (17.3°C).

Temperature

August is the warmest month, with the temperature often reaching an average high of 82.2°F (27.9°C) and an average low of 63.1°F (17.3°C).

Heat index

The average heat index in August is calculated to be 84.2°F (29°C). Exhaustion becomes probable with enduring exposure and activity, potentially causing heat cramps.
Take into consideration that the heat index values are calculated for shade and light wind conditions. The direct sun can potentially cause the heat index to increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', is what the temperature feels like to the human body when the air temperature is combined with the relative humidity. The impact of temperature is individual, as people's perception of weather may change based on their body mass, height, and physical activity. In the direct sunlight, the weather's impact can be amplified, possibly boosting the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are essentially critical for children. Kids generally face higher risks than adults as they sweat less. Along with their large skin surface compared to their small bodies and higher heat production due to their activities, their vulnerability is increased.

Humidity

The average relative humidity in August is 56%.

Rainfall

In Simi Valley, in August, during 1.5 rainfall days, 0.12" (3mm) of precipitation is typically accumulated. Throughout the year, there are 53.7 rainfall days, and 9.61" (244mm) of precipitation is accumulated.

Daylight

In August, the average length of the day is 13h and 23min.
On the first day of the month, sunrise is at 6:06 am and sunset at 7:56 pm. On the last day of August, sunrise is at 6:28 am and sunset at 7:21 pm PDT.

Sunshine

In August, the average sunshine is 12h.

UV index

The months with the highest UV index are June through August, with an average maximum UV index of 6. A UV Index estimate of 6 to 7 represents a high health hazard from unprotected exposure to Sun's UV rays for the average person.
Note: The daily maximum UV index of 6 in August interprets into the following advice:
Apply measures and align with sun safety principles. Safeguarding against skin and eye injury is pivotal. Limit direct sun exposure especially between 10 a.m. and 4 p.m., when UV radiation is at its peak. However, keep in mind that shade structures may not provide full sun protection. A hat with a broad brim is indispensable, filtering out up to half of UV rays.
Updated: Aug 25, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the hottest time of year?

August proves to be the warmest month, recording an average peak temperature of 82.2°F (27.9°C) and a minimum temperature of 63.1°F (17.3°C).

What is the average August temperature?

In August, in Simi Valley, the average high-temperature is 82.2°F (27.9°C), and the average low-temperature is 63.1°F (17.3°C). The average heat index (a.k.a. 'real feel', 'feels like'), which represents the influence of relative humidity on air temperature, in August is calculated to be 84.2°F (29°C).

What is the average humidity in August?

In August, the average relative humidity is 56%.

How much does it rain in August?

In August, the rain falls for 1.5 days. Throughout August, 0.12" (3mm) of precipitation is accumulated.

What is the average length of the day in August?

The average day length in August is 13h and 23min.

When are sunrise and sunset in August?

In August, on the first day of the month, sunrise is at 6:06 am and sunset at 7:56 pm. On the last day of the month, sunrise is at 6:28 am and sunset at 7:21 pm PDT.

How many hours of sunshine does Simi Valley have in August?

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

When is the highest UV index in Simi Valley?

June through August, with an average maximum UV index of 6, are months with the highest UV index.

How high is the UV index in August?

In August, the average daily maximum UV index is 6. A UV Index estimate of 6 to 7 represents a high health vulnerability from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in August
Simi Valley, CA

Average temperature in August - Simi Valley, CA
  • Average high temperature in August: 82.2°F

The warmest month (with the highest average high temperature) is August (82.2°F).
The month with the lowest average high temperature is December (60.1°F).

  • Average low temperature in August: 63.1°F

The month with the highest average low temperature is August (63.1°F).
The coldest month (with the lowest average low temperature) is December (46.4°F).

Average pressure in August
Simi Valley, CA

Average pressure in August - Simi Valley, CA
  • Average pressure in August: 29.91"Hg

The month with the highest atmospheric pressure is January (30.11"Hg).
The months with the lowest atmospheric pressure are June and September (29.9"Hg).

Average wind speed in August
Simi Valley, CA

Average wind speed in August - Simi Valley, CA
  • Average wind speed in August: 4.3mph

The windiest month (with the highest average wind speed) is December (6.5mph).
The calmest month (with the lowest average wind speed) is August (4.3mph).

Average humidity in August
Simi Valley, CA

Average humidity in August - Simi Valley, CA
  • Average humidity in August: 56%

The month with the highest relative humidity is June (62%).
The month with the lowest relative humidity is November (50%).

Average rainfall in August
Simi Valley, CA

Average rainfall in August - Simi Valley, CA
  • Average rainfall in August: 0.12"

The wettest month (with the highest rainfall) is February (1.93").
The driest month (with the least rainfall) is June (0.08").

Average rainfall days in August
Simi Valley, CA

Average rainfall days in August - Simi Valley, CA
  • Average rainfall days in August: 1.5 days

The month with the highest number of rainy days is March (8 days).
The months with the least rainy days are June and August (1.5 days).

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

Average daylight in August / Average sunshine in August - Simi Valley, CA
  • Average daylight in August: 13h and 2min

The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).

  • Average sunshine in August: 12h and 0min

The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The months with the least sunshine are January, February and December (Average sunshine: 6h and 48min).

Average sunshine days in August
Simi Valley, CA

Average sunshine days in August - Simi Valley, CA
  • Average sunshine days in August: 25.4 days

The month with the most sunshine days is August (25.4 days).
The month with the least sunshine days is February (20.9 days).

Average UV index in August
Simi Valley, CA

Average UV index in August - Simi Valley, CA
  • Average UV index in August: 6

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

Average cloud cover in August
Simi Valley, CA

Average cloud cover in August - Simi Valley, CA
  • Average cloud cover in August: 5

The month with the most cloud cover is March (Cloud cover 23).
The month with the least cloud cover is August (Cloud cover 5).

Average visibility in August
Simi Valley, CA

Average visibility in August - Simi 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).

Simi Valley, California, USA

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