September weather forecast and climate
Oakley, CA

Weather in September

September, the first month of the autumn, in Oakley, is also a moderately hot month, with average temperature ranging between min 57.7°F (14.3°C) and max 85.3°F (29.6°C).

Temperature

In Oakley, the average high-temperature is essentially the same as in August - a moderately hot 85.3°F (29.6°C). In September, in Oakley, the average low-temperature is 57.7°F (14.3°C).

Heat index

In September, the average heat index is appraised at a hot 87.4°F (30.8°C). Exhaustion is likely with prolonged exposure and activity. Sustaining activity may result in heat cramps.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature', 'real feel', 'apparent temperature', or 'feels like', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. This effect is individual, with diverse people perceiving weather differently for numerous reasons (differences in body mass, height, and shape, metabolic differences, pregnancy), and activity. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.

Humidity

September is the least humid month in Oakley, with an average relative humidity of 52%.

Rainfall

In September, the rain falls for 1.3 days. Throughout September, 0.08" (2mm) of precipitation is accumulated. In Oakley, during the entire year, the rain falls for 62 days and collects up to 10.16" (258mm) of precipitation.

Snowfall

January through November are months without snowfall.

Daylight

In Oakley, the average length of the day in September is 12.4h.

Sunshine

The average sunshine in Oakley is 11.2h.

UV index

The average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium health hazard from the exposure to the Sun's UV radiation for the ordinary person.
Note: The average daily UV index of 5 transform into the following instructions:
Take precautions - Protection against the skin and eye damage is obliged. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
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FAQ

What is the temperature in September in Oakley?

The average high-temperature, in September, is 85.3°F (29.6°C), while the average low-temperature is 57.7°F (14.3°C). In September, the average heat index (a.k.a. 'feels like', 'real feel'), that represents influence of the relative humidity to air temperaure, is appraised at 87.4°F (30.8°C).

What is the least humid month in Oakley?

September is the least humid month, with an average relative humidity of 52%.

What is the average humidity in September in Oakley?

In September, the average relative humidity in Oakley is 52%.

How much does it rain in Oakley in September?

In September, in Oakley, California, the rain falls for 1.3 days. Throughout September, 0.08" (2mm) of precipitation is accumulated.

When it does not snow in Oakley?

January through November are months without snowfall in Oakley.

What is the average length of the day in September in Oakley?

In September, the average length of the day in Oakley, California, is 12.4h.

How many hours of sunshine does Oakley have in September?

The average sunshine in September in Oakley, California, is 11.2h.

What is the UV index reading in September in Oakley?

In September, the average daily maximum UV index in Oakley, California, is 5. A UV Index estimate of 3 to 5 represents a medium hazard to health from unprotected exposure to the UV radiation.

Average temperature in September
Oakley, CA

Average temperature in September - Oakley, CA
  • Average high temperature in September: 85.3°F

The warmest month (with the highest average high temperature) is July (88.5°F).
The month with the lowest average high temperature is December (55°F).

  • Average low temperature in September: 57.7°F

The month with the highest average low temperature is September (57.7°F).
The coldest month (with the lowest average low temperature) is January (41.5°F).

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Average pressure in September
Oakley, CA

Average pressure in September - Oakley, CA
  • Average pressure in September: 29.92"

The month with the highest atmospheric pressure is January (30.14").
The month with the lowest atmospheric pressure is June (29.91").

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Average wind speed in September
Oakley, CA

Average wind speed in September - Oakley, CA
  • Average wind speed in September: 6.2mph

The windiest month (with the highest average wind speed) is June (7.8mph).
The calmest months (with the lowest average wind speed) are January and November (4.5mph).

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Average humidity in September
Oakley, CA

Average humidity in September - Oakley, CA
  • Average humidity in September: 52%

The month with the highest relative humidity is January (74%).
The month with the lowest relative humidity is September (52%).

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Average rainfall in September
Oakley, CA

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

The wettest month (with the highest rainfall) is February (2.09").
The driest months (with the least rainfall) are July and August (0.04").

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Average rainfall days in September
Oakley, CA

Average rainfall days in September - Oakley, CA
  • Average rainfall days in September: 1.3 days

The month with the highest number of rainy days is March (12.3 days).
The month with the least rainy days is August (0.8 days).

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Average snowfall days in September
Oakley, CA

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

The month with the highest number of snowfall days is December (0.1 days).
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
Oakley, CA

Average daylight in September / Average sunshine in September - Oakley, CA
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.8h).
The month with the shortest days is December (Average daylight: 9.6h).

  • Average sunshine in September: 11.2h

The month with the most sunshine is July (Average sunshine: 12.1h).
The month with the least sunshine is December (Average sunshine: 5.8h).

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Average sunshine days in September
Oakley, CA

Average sunshine days in September - Oakley, CA
  • Average sunshine days in September: 28.5 days

The month with the most sunshine days is August (29.8 days).
The month with the least sunshine days is March (17.7 days).

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Average UV index in September
Oakley, CA

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

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

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Average cloud cover in September
Oakley, CA

Average cloud cover in September - Oakley, CA
  • Average cloud cover in September: 8

Months with the most cloud cover are March and December (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 5).

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Average visibility in September
Oakley, CA

Average visibility in September - Oakley, CA
  • Average visibility in September: 6mi

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

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