September weather forecast
Santa Ana, CA

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Night lights of the street in Santa Ana, California, with palm trees lining the street
Night lights of the street in Santa Ana, California, with palm trees lining the street

Weather in September

September brings a slight relief from the peak summer heat in Santa Ana, with temperatures subtly decreasing. Despite this, the city continues to enjoy high quantities of sunshine and clear skies, with cloud coverage standing at just 9%. The wind speed further decreases to 4.6mph (7.4km/h), bringing about more tranquil days. Amidst these changes, Santa Ana's vibrant atmosphere remains unwavered.

Temperature

Santa Ana records an average high-temperature of a still warm 81.7°F (27.6°C) in September, maintaining a close correlation with August's 83.1°F (28.4°C). Throughout September, Santa Ana witnesses a consistent average low-temperature of 64.2°F (17.9°C).

Heat index

In September, the heat index is estimated at 84.2°F (29°C). With prolonged exposure and constant activity, one might feel exhausted and experience heat cramps.
The standards for the heat index are set for locations in shade and under light breezes. Direct sunlight can potentially boost the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'felt air temperature', ties air temperature with relative humidity to produce the perceived temperature sensation. Metabolic differences, pregnancy status, and the level of physical activity are additional factors influencing an individual's weather perception. Consider the sun's direct rays and their impact; they can potentially increase the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical to babies and toddlers. Kids often lack the knowledge about the necessity to take breaks and consume liquids. Thirst, as a late symptom of dehydration, necessitates the maintenance of hydration, particularly during enduring physical activities.

Humidity

In Santa Ana, the average relative humidity in September is 59%.

Rainfall

In Santa Ana, during September, the rain falls for 3.7 days and regularly aggregates up to 0.24" (6mm) of precipitation. Throughout the year, there are 55 rainfall days, and 7.4" (188mm) of precipitation is accumulated.

Daylight

In Santa Ana, 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

June through September, with an average maximum UV index of 6, are months with the highest UV index. A UV Index of 6 to 7 symbolizes a high threat to health from unprotected exposure to Sun's UV rays for average individuals.
Note: The UV index of 6 in September translates into these instructions:
Sustain precautions and conform to sun safety norms. Preventing sunburn is necessary. Minimize exposure to direct sunlight and seek shade from 10 a.m. to 4 p.m., when UV radiation is most intense, but remember that shade structures may not offer complete protection. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses.
Updated: Jun 26, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures?

During September, Santa Ana experiences an average high-temperature of 81.7°F (27.6°C) and a low-temperature of 64.2°F (17.9°C). The average heat index (a.k.a. 'feels like', 'apparent temperature'), which calculates the temperature value influenced by the moisture in the air, in September is estimated at 84.2°F (29°C).

What is the average humidity in September?

The average relative humidity in September in Santa Ana is 59%.

How much does it rain in September?

In Santa Ana, during September, the rain falls for 3.7 days and regularly aggregates up to 0.24" (6mm) of precipitation.

How many hours of daylight does Santa Ana have in September?

The average day length in September is 12h and 22min.

When is the sunrise / 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 many hours of sunshine does Santa Ana have in September?

The average sunshine duration in September is 10.6h.

When is the highest UV index?

The months with the highest UV index are June through September, with an average maximum UV index of 6.

What is the UV index intensity in September?

In September, the average daily maximum UV index is 6. A UV Index estimate of 6 to 7 represents a high health threat from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Santa Ana, CA

Average temperature in September - Santa Ana, CA
  • Average high temperature in September: 81.7°F

The warmest month (with the highest average high temperature) is August (83.1°F).
The month with the lowest average high temperature is December (63.7°F).

  • Average low temperature in September: 64.2°F

The month with the highest average low temperature is August (64.9°F).
The coldest month (with the lowest average low temperature) is February (50.2°F).

Average pressure in September
Santa Ana, CA

Average pressure in September - Santa Ana, 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).

Average wind speed in September
Santa Ana, CA

Average wind speed in September - Santa Ana, CA
  • Average wind speed in September: 4.6mph

The windiest month (with the highest average wind speed) is April (5.9mph).
The calmest month (with the lowest average wind speed) is September (4.6mph).

Average humidity in September
Santa Ana, CA

Average humidity in September - Santa Ana, CA
  • Average humidity in September: 59%

The month with the highest relative humidity is June (66%).
The month with the lowest relative humidity is November (52%).

Average rainfall in September
Santa Ana, CA

Average rainfall in September - Santa Ana, CA
  • Average rainfall in September: 0.24"

The wettest month (with the highest rainfall) is December (1.54").
The driest month (with the least rainfall) is June (0.08").

Average rainfall days in September
Santa Ana, CA

Average rainfall days in September - Santa Ana, CA
  • Average rainfall days in September: 3.7 days

The month with the highest number of rainy days is March (7.1 days).
The month with the least rainy days is June (1.7 days).

Average daylight in September /
Average sunshine in September
Santa Ana, CA

Average daylight in September / Average sunshine in September - Santa Ana, 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: 10h and 0min).

  • Average sunshine in September: 10h and 4min

The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).

Average sunshine days in September
Santa Ana, CA

Average sunshine days in September - Santa Ana, CA
  • Average sunshine days in September: 22.8 days

The month with the most sunshine days is January (25 days).
The month with the least sunshine days is February (20.8 days).

Average UV index in September
Santa Ana, CA

Average UV index in September - Santa Ana, CA
  • Average UV index in September: 6

The months with the highest UV index are June, July, August and September (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 4).

Average cloud cover in September
Santa Ana, CA

Average cloud cover in September - Santa Ana, CA
  • Average cloud cover in September: 9

The month with the most cloud cover is December (Cloud cover 23).
The month with the least cloud cover is August (Cloud cover 5).

Average visibility in September
Santa Ana, CA

Average visibility in September - Santa Ana, 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).

Santa Ana, California, USA

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