September weather forecast
Placentia, CA

Weather in September

The first month of the autumn, September, is still a warm month in Placentia, California, with temperature in the range of an average low of 64.8°F (18.2°C) and an average high of 84°F (28.9°C).

Temperature

In Placentia, the average high-temperature in September is practically the same as in August - a still moderately hot 84°F (28.9°C). In Placentia, the average low-temperature is 64.8°F (18.2°C).

Heat index

The average heat index in September is estimated at a tropical 86°F (30°C). Constant exposure and activity lead to possible fatigue. Prolonged exercise may result in heat cramps.
Take into consideration that the heat index values are calculated for shade and light wind conditions. With 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 'feels like', 'apparent temperature', 'real feel', or 'felt air temperature', is a measure of how hot it feels when the actual air humidity is factored in. Additional factors like wind, metabolic differences, pregnancy, and activity influence one's weather impression. Be aware that direct exposure to sunlight increases heat impact and may raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. 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

The average relative humidity in September is 56%.

Rainfall

In Placentia, California, it is raining for 3 days, with typically 0.16" (4mm) of accumulated precipitation. Throughout the year, there are 53.2 rainfall days, and 7.72" (196mm) of precipitation is accumulated.

Daylight

In Placentia, 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 7:17 pm. On the last day of the month, sunrise is at 6:45 am and sunset at 6:37 pm PDT.

Sunshine

In Placentia, the average sunshine in September is 10.7h.

UV index

The months with the highest UV index are June through September, with an average maximum UV index of 6. A UV Index of 6 to 7 symbolizes a high health vulnerability from unsafe exposure to UV radiation for ordinary individuals.
Note: In September, the average maximum UV index of 6 translate into the following recommendations:
Take precautions and utilize sun safety practices. Protection against skin and eye damage is required. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.
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FAQ

What is the temperature in September in Placentia?

The average high-temperature, in September, in Placentia, is 84°F (28.9°C), while the average low-temperature is 64.8°F (18.2°C). The average heat index (a.k.a. 'apparent temperature', 'real feel'), which combines relative humidity and air temperature, in September is estimated at 86°F (30°C).

What is the average humidity in September in Placentia?

The average relative humidity in September in Placentia is 56%.

How many days does it rain in September in Placentia?

In September, in Placentia, the rain falls for 3 days. Throughout September, 0.16" (4mm) of precipitation is accumulated.

How many hours of daylight does Placentia have in September?

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

What time are sunrise and sunset in September in Placentia?

In September, on the first day of the month, sunrise is at 6:25 am and sunset at 7:17 pm. On the last day of the month, in Placentia, sunrise is at 6:45 am and sunset at 6:37 pm PDT.

How long on average sun shines in September in Placentia?

The average sunshine duration in September in Placentia, California, is 10.7h.

What are the months with the highest UV index in Placentia?

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

What is the UV index intensity in September in Placentia?

The average daily maximum UV index in September in Placentia is 6. A UV Index reading of 6 to 7 represents a high health risk from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Placentia, CA

Average temperature in September - Placentia, CA
  • Average high temperature in September: 84°F

The warmest month (with the highest average high temperature) is August (85.3°F).
The month with the lowest average high temperature is December (64.2°F).

  • Average low temperature in September: 64.8°F

The month with the highest average low temperature is August (65.7°F).
The coldest month (with the lowest average low temperature) is February (49.6°F).

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Average pressure in September
Placentia, CA

Average pressure in September - Placentia, 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
Placentia, CA

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

The windiest month (with the highest average wind speed) is April (5.8mph).
The calmest month (with the lowest average wind speed) is September (4.5mph).

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Average humidity in September
Placentia, CA

Average humidity in September - Placentia, CA
  • Average humidity in September: 56%

The month with the highest relative humidity is June (63%).
The month with the lowest relative humidity is November (50%).

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Average rainfall in September
Placentia, CA

Average rainfall in September - Placentia, CA
  • Average rainfall in September: 0.16"

The wettest month (with the highest rainfall) is December (1.65").
The driest month (with the least rainfall) is June (0.04").

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Average rainfall days in September
Placentia, CA

Average rainfall days in September - Placentia, CA
  • Average rainfall days in September: 3 days

The month with the highest number of rainy days is March (7.4 days).
The month with the least rainy days is June (1.4 days).

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

Average daylight in September / Average sunshine in September - Placentia, CA
  • Average daylight in September: 12h and 22min

The month with the longest days is June (Average daylight: 14h and 22min).
The month with the shortest days is December (Average daylight: 9h and 56min).

  • Average sunshine in September: 10h and 42min

The month with the most sunshine is July (Average sunshine: 12h and 6min).
The months with the least sunshine are February and December (Average sunshine: 6h and 48min).

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Average sunshine days in September
Placentia, CA

Average sunshine days in September - Placentia, CA
  • Average sunshine days in September: 24.4 days

The month with the most sunshine days is August (26.7 days).
The month with the least sunshine days is February (20.7 days).

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Average UV index in September
Placentia, CA

Average UV index in September - Placentia, 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).

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Average cloud cover in September
Placentia, CA

Average cloud cover in September - Placentia, 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).

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Average visibility in September
Placentia, CA

Average visibility in September - Placentia, 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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