September weather forecast and climate
Perris, CA

Landscape in the State Recreation Area on Lake Perris, California
Landscape in the State Recreation Area on Lake Perris, California

Weather in September

September, the first month of the autumn, in Perris, is also a moderately hot month, with average temperature varying between 85.8°F (29.9°C) and 61.3°F (16.3°C).

Temperature

In September, the average high-temperature is practically the same as in August - a moderately hot 85.8°F (29.9°C). In Perris, the average low-temperature is 61.3°F (16.3°C).

Heat index

The average heat index in September is calculated to a hot 87.4°F (30.8°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. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature', 'feels like', 'real feel', or 'apparent temperature', combines air temperature and relative humidity to represent a human perceived temperature equivalent. Additional factors like activity, clothing, metabolic differences, and pregnancy affect individual temperature impact. 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 especially crucial for babies and toddlers. 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

In September, the average relative humidity in Perris is 49%.

Rainfall

In September, the rain falls for 3.5 days. Throughout September, 0.2" (5mm) of precipitation is accumulated. Throughout the year, in Perris, California, there are 55.7 rainfall days, and 7.05" (179mm) of precipitation is accumulated.

Snowfall

In Perris snow does not fall in January, March through December.

Daylight

The average length of the day in September is 12.4h.

Sunshine

In September, the average sunshine in Perris is 10.6h.

UV index

The average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high threat to health from the exposure to the Sun's UV radiation for the average person.
Note: The average daily UV index of 6 in September transform into the following instructions:
Take precautions and adopt sun safety practices. Protection against sunburn is obliged. 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. 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.
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FAQ

What is the temperature in September in Perris?

In September, in Perris, California, the average high-temperature is 85.8°F (29.9°C), and the average low-temperature is 61.3°F (16.3°C). The average heat index (a.k.a. 'real feel', 'felt air temperature'), that calculates temperature value influenced by the moisture in the air, in September is calculated to 87.4°F (30.8°C).

What is the average humidity in September in Perris?

In September, the average relative humidity is 49%.

How many days does it rain in September in Perris?

In Perris, California, during September, the rain falls for 3.5 days and regularly aggregates up to 0.2" (5mm) of precipitation.

When it does not snow in Perris?

January, March through December are months without snowfall.

How many hours of daylight does Perris have in September?

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

How many hours of sunshine does Perris have in September?

In September, the average sunshine is 10.6h.

What is the UV index intensity in September in Perris?

In September, the average daily maximum UV index in Perris is 6. A UV Index estimate of 6 to 7 represents a high health vulnerability from the exposure to the Sun's UV rays.

Average temperature in September
Perris, CA

Average temperature in September - Perris, CA
  • Average high temperature in September: 85.8°F

The warmest month (with the highest average high temperature) is August (89.6°F).
The month with the lowest average high temperature is December (61°F).

  • Average low temperature in September: 61.3°F

The month with the highest average low temperature is August (63.3°F).
The coldest month (with the lowest average low temperature) is December (43°F).

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Average pressure in September
Perris, CA

Average pressure in September - Perris, CA
  • Average pressure in September: 29.87"

The month with the highest atmospheric pressure is January (30.1").
The month with the lowest atmospheric pressure is June (29.85").

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Average wind speed in September
Perris, CA

Average wind speed in September - Perris, CA
  • Average wind speed in September: 4.2mph

The windiest month (with the highest average wind speed) is April (5.5mph).
The calmest months (with the lowest average wind speed) are August and September (4.2mph).

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Average humidity in September
Perris, CA

Average humidity in September - Perris, CA
  • Average humidity in September: 49%

The month with the highest relative humidity is May (60%).
The month with the lowest relative humidity is August (47%).

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Average rainfall in September
Perris, CA

Average rainfall in September - Perris, CA
  • Average rainfall in September: 0.2"

The wettest month (with the highest rainfall) is December (1.38").
The driest month (with the least rainfall) is June (0.04").

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Average rainfall days in September
Perris, CA

Average rainfall days in September - Perris, CA
  • Average rainfall days in September: 3.5 days

The month with the highest number of rainy days is March (7.2 days).
The month with the least rainy days is June (1.3 days).

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Average snowfall in September
Perris, CA

Average snowfall in September - Perris, CA
  • Average snowfall in September: 0"

The month with the highest snowfall is February (0.04").
Months with the least snowfall are January, March, April, May, June, July, August, September, October, November and December (0").

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Average snowfall days in September
Perris, CA

Average snowfall days in September - Perris, CA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (0.2 days).
Months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).

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

Average daylight in September / Average sunshine in September - Perris, 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: 10.6h

The month with the most sunshine is July (Average sunshine: 12.1h).
The month with the least sunshine is December (Average sunshine: 6.7h).

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Average sunshine days in September
Perris, CA

Average sunshine days in September - Perris, CA
  • Average sunshine days in September: 23.4 days

The month with the most sunshine days is June (26.9 days).
The month with the least sunshine days is February (21.6 days).

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Average UV index in September
Perris, CA

Average UV index in September - Perris, CA
  • Average UV index in September: 6

The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is December (UV index 3).

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Average cloud cover in September
Perris, CA

Average cloud cover in September - Perris, CA
  • Average cloud cover in September: 8

Months with the most cloud cover are March and December (Cloud cover 24).
The month with the least cloud cover is August (Cloud cover 5).

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Average visibility in September
Perris, CA

Average visibility in September - Perris, 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).

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