September weather forecast
August, CA

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Weather in September

The first month of the autumn, September, is still a hot month in August, California, with an average temperature varying between 58.8°F (14.9°C) and 88.7°F (31.5°C).

Temperature

The advent of September brings an average high-temperature of a still hot 88.7°F (31.5°C), almost identical to the preceding month. The anticipated average low-temperature for September in August, a mild 58.8°F (14.9°C), shows a substantial deviation from the daytime maximums.

Heat index

In September, the heat index is appraised at a tropical 91.4°F (33°C). Exercise extra preventive actions, heat cramps and heat exhaustion are plausible. Continuous activity could result in heatstroke.
Heat index's context suggests values are appropriate for shady areas and slight breezes. Facing direct sunlight may hike up the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', is a measure of how hot it feels when the actual air humidity is factored in. The effect is experienced differently by individuals, hinging on unique characteristics such as body mass, stature, and level of activity. 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 extremely vital to babies and toddlers. Young ones often ignore the need to take a break and drink fluids. Thirst is a late-stage symptom of dehydration - hence, maintaining hydration, particularly during extended physical activities, is crucial.

Humidity

In August, California, the average relative humidity in September is 46%.

Rainfall

January through July, September through December are months with rainfall in August. September is the first month it rains. Throughout September, in the average 1.6 rainfall days, it receives 0.08" (2mm) of precipitation. In August, during the entire year, the rain falls for 64.2 days and collects up to 11.34" (288mm) of precipitation.

Snowfall

January through November are months without snowfall in August.

Daylight

The average length of the day in September in August is 12h and 25min.
On the first day of September, sunrise is at 6:35 am and sunset at 7:33 pm. On the last day of the month, sunrise is at 7:00 am and sunset at 6:48 pm PDT.

Sunshine

In September, the average sunshine in August is 11.4h.

UV index

In August, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for the ordinary person.
Note: In September, the maximum UV index of 5 suggests these recommendations:
Ensure safety - Sun damage prevention is strongly urged. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun.
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Frequently asked questions

How hot is it in August in September?

September temperatures in August, California, vary between a high-temperature of 88.7°F (31.5°C) and a low-temperature of 58.8°F (14.9°C). The average heat index (a.k.a. 'felt air temperature', 'real feel'), which combines air temperature and relative humidity, in September is appraised at 91.4°F (33°C).

What is the average humidity in September in August?

The average relative humidity in September is 46%.

When does it start to rain in August?

September is the first month it rains in August, California. Throughout September, in the average 1.6 rainfall days, it receives 0.08" (2mm) of precipitation.

When it does not snow in August?

In August, California, snow does not fall in January through November.

How many hours of daylight does August have in September?

In September, the average day length in August, California, is 12h and 25min.

What time are sunrise and sunset in September in August?

On the first day of September in August, sunrise is at 6:35 am and sunset at 7:33 pm. On the last day of the month, sunrise is at 7:00 am and sunset at 6:48 pm PDT.

How many hours of sunshine does August have in September?

In September, the average sunshine duration in August, California, is 11.4h.

What is the UV index intensity in September in August?

In August, California, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium hazard to health from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
August, CA

Average temperature in September - August, CA
  • Average high temperature in September: 88.7°F

The warmest month (with the highest average high temperature) is July (94.3°F).
The month with the lowest average high temperature is December (55.2°F).

  • Average low temperature in September: 58.8°F

The month with the highest average low temperature is August (59.5°F).
The coldest month (with the lowest average low temperature) is December (41.2°F).

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Average pressure in September
August, CA

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

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

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Average wind speed in September
August, CA

Average wind speed in September - August, CA
  • Average wind speed in September: 5.8mph

The windiest month (with the highest average wind speed) is June (7.1mph).
The calmest month (with the lowest average wind speed) is November (4.7mph).

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Average humidity in September
August, CA

Average humidity in September - August, CA
  • Average humidity in September: 46%

The month with the highest relative humidity is January (73%).
The month with the lowest relative humidity is July (44%).

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Average rainfall in September
August, CA

Average rainfall in September - August, CA
  • Average rainfall in September: 0.08"

The wettest month (with the highest rainfall) is February (2.13").
The driest month (with the least rainfall) is August (0").

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Average rainfall days in September
August, CA

Average rainfall days in September - August, CA
  • Average rainfall days in September: 1.6 days

The month with the highest number of rainy days is March (12 days).
The month with the least rainy days is August (0.7 days).

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Average snowfall days in September
August, CA

Average snowfall days in September - August, CA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is December (0.1 days).
The months with the least snowfall days are January, February, March, April, May, June, July, August, September, October and November (0 days).

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

Average daylight in September / Average sunshine in September - August, CA
  • Average daylight in September: 12h and 2min

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 September: 11h and 2min

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

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Average sunshine days in September
August, CA

Average sunshine days in September - August, CA
  • Average sunshine days in September: 28 days

The month with the most sunshine days is August (30.2 days).
The month with the least sunshine days is March (17.8 days).

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Average UV index in September
August, CA

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

The months with the highest UV index are June and July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 3).

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Average cloud cover in September
August, CA

Average cloud cover in September - August, CA
  • Average cloud cover in September: 7

The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 4).

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Average visibility in September
August, CA

Average visibility in September - August, CA
  • Average visibility in September: 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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August, California, USA

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