September weather forecast and climate
Castaic, CA

Weather in September

September, the first month of the autumn, in Castaic, is also a moderately hot month, with average temperature ranging between max 84.7°F (29.3°C) and min 61°F (16.1°C).

Temperature

In Castaic, the average high-temperature in September is essentially the same as in August - a warm 84.7°F (29.3°C). The average low-temperature, in Castaic, is 61°F (16.1°C).

Heat index

The average heat index is calculated to 84.7°F (29.3°C). Exhaustion is likely with prolonged exposure and activity. Sustaining activity may result in heat cramps.
Note that heat index values are valued for light wind and location in the shade. With the exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature', 'apparent temperature', 'real feel', or 'feels like', is calculated by taking the relative humidity value for a specific location and factoring it into the air temperature reading. This effect is individual, with diverse people perceiving weather differently for numerous reasons (differences in body mass, height, and shape, metabolic differences, wind), and activity. Be aware that direct exposure to sunlight increases heat impact, and may raise the heat index additionally, by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.

Humidity

The average relative humidity in September is 44%.

Rainfall

In September, the rain falls for 2.3 days. Throughout September, 0.08" (2mm) of precipitation is accumulated. Throughout the year, there are 42.2 rainfall days, and 6.77" (172mm) of precipitation is accumulated.

Daylight

In Castaic, the average length of the day is 12.4h.

Sunshine

The average sunshine in Castaic is 10.9h.

UV index

In September, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from unprotected exposure to the Sun's UV rays for the average person.
Note: The daily maximum UV index of 5 in September interpret into the following advice:
Take precautions - Protection against the skin and eye damage is obliged. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. 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.
[Resources]

FAQ

What is the temperature in September in Castaic?

In September, in Castaic, the average high-temperature is 84.7°F (29.3°C), and the average low-temperature is 61°F (16.1°C). The average heat index (a.k.a. 'felt air temperature', 'feels like'), that represents influence of the relative humidity to air temperaure, in September is calculated to 84.7°F (29.3°C).

What is the average humidity in September in Castaic?

The average relative humidity in September in Castaic, California, is 44%.

How many days does it rain in September in Castaic?

In Castaic, California, in September, during 2.3 rainfall days, 0.08" (2mm) of precipitation is typically accumulated.

How many hours of daylight does Castaic have in September?

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

How many hours of sunshine does Castaic have in September?

In September, the average sunshine in Castaic is 10.9h.

How high is the UV index in September in Castaic?

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

Average temperature in September
Castaic, CA

Average temperature in September - Castaic, CA
  • Average high temperature in September: 84.7°F

The warmest month (with the highest average high temperature) is August (88.2°F).
The month with the lowest average high temperature is December (59.5°F).

  • Average low temperature in September: 61°F

The month with the highest average low temperature is August (63.7°F).
The coldest month (with the lowest average low temperature) is December (42.3°F).

[Resources]

Average pressure in September
Castaic, CA

Average pressure in September - Castaic, CA
  • Average pressure in September: 29.9"

The month with the highest atmospheric pressure is January (30.11").
The month with the lowest atmospheric pressure is June (29.88").

[Resources]

Average wind speed in September
Castaic, CA

Average wind speed in September - Castaic, CA
  • Average wind speed in September: 5mph

The windiest months (with the highest average wind speed) are January and December (7.3mph).
The calmest month (with the lowest average wind speed) is August (4.9mph).

[Resources]

Average humidity in September
Castaic, CA

Average humidity in September - Castaic, CA
  • Average humidity in September: 44%

The month with the highest relative humidity is March (56%).
Months with the lowest relative humidity are August and October (43%).

[Resources]

Average rainfall in September
Castaic, CA

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

The wettest month (with the highest rainfall) is December (1.42").
The driest months (with the least rainfall) are June and August (0.04").

[Resources]

Average rainfall days in September
Castaic, CA

Average rainfall days in September - Castaic, CA
  • Average rainfall days in September: 2.3 days

The month with the highest number of rainy days is March (6.9 days).
The month with the least rainy days is June (0.7 days).

[Resources]

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

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

The month with the longest days is June (Average daylight: 14.4h).
The month with the shortest days is December (Average daylight: 9.9h).

  • Average sunshine in September: 10.9h

Months with the most sunshine are June and July (Average sunshine: 12.1h).
The month with the least sunshine is February (Average sunshine: 6.7h).

[Resources]

Average sunshine days in September
Castaic, CA

Average sunshine days in September - Castaic, CA
  • Average sunshine days in September: 27 days

The month with the most sunshine days is August (28.7 days).
The month with the least sunshine days is February (21.5 days).

[Resources]

Average UV index in September
Castaic, CA

Average UV index in September - Castaic, 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 February, November and December (UV index 3).

[Resources]

Average cloud cover in September
Castaic, CA

Average cloud cover in September - Castaic, CA
  • Average cloud cover in September: 6

The month with the most cloud cover is March (Cloud cover 23).
The month with the least cloud cover is August (Cloud cover 4).

[Resources]

Average visibility in September
Castaic, CA

Average visibility in September - Castaic, 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).

[Resources]