September weather forecast
South Whittier, CA

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Weather in September

The first month of the autumn, September, is still a warm month in South Whittier, California, with an average temperature varying between 84.2°F (29°C) and 65.1°F (18.4°C).

Temperature

With the arrival of September, South Whittier's average high-temperature registers at a still moderately hot 84.2°F (29°C), indicating a subtle variation from the previous month. South Whittier records a consistent low-temperature of 65.1°F (18.4°C) during September nights.

Heat index

During September, the heat index is calculated to be a tropical 86°F (30°C). Uninterrupted exposure and activity might result in fatigue, potentially causing heat cramps.
Consider that heat index readings are for situations in the shade and light wind. An exposure to direct sunlight may lift the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', gauges the sensation of temperature factoring in the air's moisture content. The individual's experience of temperature can be shaped by numerous aspects such as metabolic variations, physical exertion, and attire. Be mindful that being in direct sunlight might mean feeling hotter, with the heat index rising by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are essentially critical for children. Children typically face more danger than adults as their sweat production is usually lower. Additionally, the bigger skin surface compared to their small size and the increased heat due to their activeness exacerbate the risk.

Humidity

The average relative humidity in September is 54%.

Rainfall

In South Whittier, during September, the rain falls for 1.3 days and regularly aggregates up to 0.04" (1mm) of precipitation. Throughout the year, there are 27.3 rainfall days, and 1.97" (50mm) of precipitation is accumulated.

Daylight

In South Whittier, the average length of the day in September is 12h and 22min.
On the first day of the month, sunrise is at 6:26 am and sunset at 7:17 pm. On the last day of September, in South Whittier, California, sunrise is at 6:46 am and sunset at 6:37 pm PDT.

Sunshine

In September, the average sunshine in South Whittier is 10.6h.

UV index

In South Whittier, the average daily maximum UV index in September is 6. A UV Index value of 6 to 7 symbolizes a high threat to health from unsafe exposure to UV radiation for average individuals.
Note: The maximum daily UV index of 6 in September converts into the following recommendations:
Adopt measures and apply sun safety strategies. Shielding from skin and eye damage is necessary. The Sun's UV radiation is most potent between the hours of 10 a.m. and 4 p.m. Try to avoid direct sunlight during this time. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes.
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Frequently asked questions

How hot is September in South Whittier?

The average high-temperature, in September, in South Whittier, is 84.2°F (29°C), while the average low-temperature is 65.1°F (18.4°C). The average heat index (a.k.a. 'apparent temperature', 'real feel'), which combines relative humidity and air temperature, in September is calculated to be 86°F (30°C).

What is the average humidity in September in South Whittier?

In September, the average relative humidity is 54%.

How much does it rain in South Whittier in September?

In South Whittier, California, in September, during 1.3 rainfall days, 0.04" (1mm) of precipitation is typically accumulated.

What is the average length of the day in September in South Whittier?

In South Whittier, California, the average day length in September is 12h and 22min.

When are sunrise and sunset in September in South Whittier?

In September, on the first day of the month, sunrise is at 6:26 am and sunset at 7:17 pm. On the last day of the month, sunrise is at 6:46 am and sunset at 6:37 pm PDT.

How long on average sun shines in September in South Whittier?

In South Whittier, the average sunshine duration in September is 10.6h.

What is the UV index intensity in September in South Whittier?

In South Whittier, the average daily maximum UV index in September is 6. A UV Index value of 6 to 7 symbolizes 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 September
South Whittier, CA

Average temperature in September - South Whittier, CA
  • Average high temperature in September: 84.2°F

The warmest month (with the highest average high temperature) is August (85.6°F).
The month with the lowest average high temperature is December (64.8°F).

  • Average low temperature in September: 65.1°F

The month with the highest average low temperature is August (65.8°F).
The coldest month (with the lowest average low temperature) is February (49.8°F).

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Average pressure in September
South Whittier, CA

Average pressure in September - South Whittier, CA
  • Average pressure in September: 29.89"Hg

The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).

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Average wind speed in September
South Whittier, CA

Average wind speed in September - South Whittier, CA
  • Average wind speed in September: 4.7mph

The windiest month (with the highest average wind speed) is April (6mph).
The calmest months (with the lowest average wind speed) are September and October (4.7mph).

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Average humidity in September
South Whittier, CA

Average humidity in September - South Whittier, CA
  • Average humidity in September: 54%

The month with the highest relative humidity is June (63%).
The month with the lowest relative humidity is November (48%).

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Average rainfall in September
South Whittier, CA

Average rainfall in September - South Whittier, CA
  • Average rainfall in September: 0.04"

The wettest month (with the highest rainfall) is December (0.47").
The driest month (with the least rainfall) is June (0").

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Average rainfall days in September
South Whittier, CA

Average rainfall days in September - South Whittier, CA
  • Average rainfall days in September: 1.3 days

The month with the highest number of rainy days is March (4.6 days).
The month with the least rainy days is June (0.5 days).

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Average daylight in September /
Average sunshine in September
South Whittier, CA

Average daylight in September / Average sunshine in September - South Whittier, CA
  • Average daylight in September: 12h 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 September: 10h and 4min

The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The months with the least sunshine are January, February and December (Average sunshine: 6h and 48min).

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Average sunshine days in September
South Whittier, CA

Average sunshine days in September - South Whittier, CA
  • Average sunshine days in September: 27.6 days

The month with the most sunshine days is June (29.3 days).
The month with the least sunshine days is February (23.8 days).

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Average UV index in September
South Whittier, CA

Average UV index in September - South Whittier, CA
  • Average UV index in September: 6

The month with the highest UV index is August (UV index 7).
The months with the lowest UV index are February, November and December (UV index 4).

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Average cloud cover in September
South Whittier, CA

Average cloud cover in September - South Whittier, CA
  • Average cloud cover in September: 8

The months with the most cloud cover are March and December (Cloud cover 22).
The month with the least cloud cover is August (Cloud cover 6).

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Average visibility in September
South Whittier, CA

Average visibility in September - South Whittier, 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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South Whittier, California, USA

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