September weather forecast
Yorba Linda, CA

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Weather in September

The first month of the autumn, September, is also a moderately hot month in Yorba Linda, California, with an average temperature ranging between min 64.6°F (18.1°C) and max 84.4°F (29.1°C).

Temperature

The unfolding of September shows an average high-temperature of a warm 84.4°F (29.1°C), indicating a slight variance from August's 86.7°F (30.4°C). An average temperature of 64.6°F (18.1°C) marks the nights in Yorba Linda in September.

Heat index

September's mean heat index is evaluated at a tropical 86°F (30°C). A sense of exhaustion might occur with extended exposure and activity, potentially causing heat cramps.
Note that heat index values are valued for light wind and location in the shade. Facing direct sunlight may hike up the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'feels like', combines air temperature and relative humidity to represent a human perceived temperature equivalent. Additional factors encompassing metabolic differences, the level of physical activity, and clothing can impact the individual's perception of temperature. Considering the impact of direct sunlight, it's possible for the heat index to surge by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially vital to children. Young individuals usually face greater risks than adults as their sweat production is less. Also, their larger skin surface relative to their small bodies and the high heat generation due to their activity contributes to their vulnerability.

Humidity

The average relative humidity in September in Yorba Linda is 54%.

Rainfall

In Yorba Linda, during September, the rain falls for 2.6 days and regularly aggregates up to 0.16" (4mm) of precipitation. In Yorba Linda, during the entire year, the rain falls for 49 days and collects up to 6.97" (177mm) of precipitation.

Daylight

In Yorba Linda, the average length of the day in September is 12h and 22min.
On the first day of September, sunrise is at 6:25 am and sunset at 7:16 pm. On the last day of the month, sunrise is at 6:45 am and sunset at 6:36 pm PDT.

Sunshine

In September, the average sunshine is 10.6h.

UV index

The average daily maximum UV index in September is 6. A UV Index estimate of 6 to 7 represents a high health vulnerability from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: The maximum daily UV index of 6 during September translates into the following directions:
Prevent overexposure. Protection from the sun's harmful effects is needed. Avoid direct Sun exposure and seek shade between 10 a.m. and 4 p.m., when UV radiation is at its peak, but keep in mind that not all shade structures provide complete protection. Boost your sun resistance with garments that are densely woven yet spacious.
Updated: Aug 21, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

Is it hot during September?

The average high-temperature, in September, in Yorba Linda, is 84.4°F (29.1°C), while the average low-temperature is 64.6°F (18.1°C). In September, the average heat index (a.k.a. 'apparent temperature', 'feels like'), which combines relative humidity and air temperature, is evaluated at 86°F (30°C).

What is the average humidity in September?

The average relative humidity in September is 54%.

How much does it rain in September?

In Yorba Linda, California, in September, during 2.6 rainfall days, 0.16" (4mm) of precipitation is typically accumulated.

How many hours of daylight does Yorba Linda have in September?

In Yorba Linda, the average day length in September is 12h and 22min.

When are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:25 am and sunset at 7:16 pm. On the last day of the month, sunrise is at 6:45 am and sunset at 6:36 pm PDT.

How long on average sun shines in September?

In Yorba Linda, the average sunshine duration in September is 10.6h.

How high is the UV index in September?

The average daily maximum UV index in September is 6. A UV Index reading of 6 to 7 represents a high health threat 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
Yorba Linda, CA

Average temperature in September - Yorba Linda, CA
  • Average high temperature in September: 84.4°F

The warmest month (with the highest average high temperature) is August (86.7°F).
The month with the lowest average high temperature is December (64°F).

  • Average low temperature in September: 64.6°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 (48.9°F).

Average pressure in September
Yorba Linda, CA

Average pressure in September - Yorba Linda, CA
  • Average pressure in September: 29.88"Hg

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

Average wind speed in September
Yorba Linda, CA

Average wind speed in September - Yorba Linda, CA
  • Average wind speed in September: 4.5mph

The windiest month (with the highest average wind speed) is April (5.7mph).
The calmest month (with the lowest average wind speed) is September (4.5mph).

Average humidity in September
Yorba Linda, CA

Average humidity in September - Yorba Linda, CA
  • Average humidity in September: 54%

The months with the highest relative humidity are May and June (61%).
The month with the lowest relative humidity is November (49%).

Average rainfall in September
Yorba Linda, CA

Average rainfall in September - Yorba Linda, CA
  • Average rainfall in September: 0.16"

The wettest month (with the highest rainfall) is December (1.54").
The driest month (with the least rainfall) is June (0.04").

Average rainfall days in September
Yorba Linda, CA

Average rainfall days in September - Yorba Linda, CA
  • Average rainfall days in September: 2.6 days

The month with the highest number of rainy days is March (6.8 days).
The month with the least rainy days is June (1.2 days).

Average daylight in September /
Average sunshine in September
Yorba Linda, CA

Average daylight in September / Average sunshine in September - Yorba Linda, 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 month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 48min).

Average sunshine days in September
Yorba Linda, CA

Average sunshine days in September - Yorba Linda, CA
  • Average sunshine days in September: 24.1 days

The month with the most sunshine days is August (25.9 days).
The month with the least sunshine days is February (21.2 days).

Average UV index in September
Yorba Linda, CA

Average UV index in September - Yorba Linda, 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 January, February, November and December (UV index 4).

Average cloud cover in September
Yorba Linda, CA

Average cloud cover in September - Yorba Linda, 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 5).

Average visibility in September
Yorba Linda, CA

Average visibility in September - Yorba Linda, 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).

Yorba Linda, California, USA

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