September weather forecast and climate
Etiwanda, CA

Weather in September

September, the first month of the autumn, in Etiwanda, is still a tropical month, with temperature in the range of an average low of 63.7°F (17.6°C) and an average high of 88.3°F (31.3°C).

Temperature

In September, the average high-temperature is almost the same as in August - a still tropical 88.3°F (31.3°C). In September, in Etiwanda, the average low-temperature is 63.7°F (17.6°C).

Heat index

In September, the average heat index is appraised at a tropical 89.2°F (31.8°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 'apparent temperature', 'feels like', 'real feel', or 'felt air temperature', combines air temperature and relative humidity to represent a human perceived temperature equivalent. Additional factors like pregnancy, clothing, differences in body mass, height, and shape, and activity influence one's weather impression. 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

In September, the average relative humidity is 43%.

Rainfall

In Etiwanda, during 1.8 rainfall days, 0.08" (2mm) of precipitation is typically accumulated. Throughout the year, there are 42.3 rainfall days, and 4.53" (115mm) of precipitation is accumulated.

Snowfall

January, March through December are months without snowfall.

Daylight

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

Sunshine

In September, the average sunshine in Etiwanda, California, is 10.7h.

UV index

The average daily maximum UV index in Etiwanda is 6. A UV Index reading of 6 to 7 represents a high health vulnerability from the exposure to the Sun's UV radiation for the ordinary person.
Note: In September, the average maximum UV index of 6 translate into the following recommendations:
Take precautions and adopt sun safety practices. Protection against sunburn is obliged. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
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FAQ

What is the temperature in September in Etiwanda?

In Etiwanda, California, in September, the average high-temperature is 88.3°F (31.3°C), and the average low-temperature is 63.7°F (17.6°C). The average heat index (a.k.a. 'feels like', 'felt air temperature'), that combines air temperature and relative humidity, in September is calculated to 89.2°F (31.8°C).

What is the average humidity in September in Etiwanda?

In Etiwanda, the average relative humidity in September is 43%.

How much does it rain in Etiwanda in September?

In Etiwanda, in September, during 1.8 rainfall days, 0.08" (2mm) of precipitation is typically accumulated.

When it does not snow in Etiwanda?

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

How many hours of daylight does Etiwanda have in September?

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

How many hours of sunshine does Etiwanda have in September?

In September, the average sunshine in Etiwanda, California, is 10.7h.

What is the UV index intensity in September in Etiwanda?

In September, the average daily maximum UV index is 6. A UV Index estimate of 6 to 7 represents a high health threat from unprotected exposure to the UV radiation.

Average temperature in September
Etiwanda, CA

Average temperature in September - Etiwanda, CA
  • Average high temperature in September: 88.3°F

The warmest month (with the highest average high temperature) is August (91.8°F).
The month with the lowest average high temperature is December (61.7°F).

  • Average low temperature in September: 63.7°F

The month with the highest average low temperature is August (66.6°F).
The coldest months (with the lowest average low temperature) are February and December (45.3°F).

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Average pressure in September
Etiwanda, CA

Average pressure in September - Etiwanda, CA
  • Average pressure in September: 29.88"

The month with the highest atmospheric pressure is January (30.1").
The month with the lowest atmospheric pressure is June (29.86").

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Average wind speed in September
Etiwanda, CA

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

The windiest month (with the highest average wind speed) is May (5.9mph).
The calmest month (with the lowest average wind speed) is September (4.5mph).

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Average humidity in September
Etiwanda, CA

Average humidity in September - Etiwanda, CA
  • Average humidity in September: 43%

Months with the highest relative humidity are February, March and May (53%).
The month with the lowest relative humidity is August (41%).

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Average rainfall in September
Etiwanda, CA

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

The wettest month (with the highest rainfall) is February (0.98").
The driest month (with the least rainfall) is June (0.04").

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Average rainfall days in September
Etiwanda, CA

Average rainfall days in September - Etiwanda, CA
  • Average rainfall days in September: 1.8 days

The month with the highest number of rainy days is March (6.3 days).
The month with the least rainy days is June (0.9 days).

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Average snowfall days in September
Etiwanda, CA

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

The month with the highest number of snowfall days is February (0.1 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
Etiwanda, CA

Average daylight in September / Average sunshine in September - Etiwanda, 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: 10.7h

The month with the most sunshine is July (Average sunshine: 12.1h).
Months with the least sunshine are February and December (Average sunshine: 6.9).

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Average sunshine days in September
Etiwanda, CA

Average sunshine days in September - Etiwanda, CA
  • Average sunshine days in September: 26 days

The month with the most sunshine days is June (28.3 days).
The month with the least sunshine days is February (22.8 days).

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Average UV index in September
Etiwanda, CA

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

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

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Average cloud cover in September
Etiwanda, CA

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

Months with the most cloud cover are February and December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 5).

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Average visibility in September
Etiwanda, CA

Average visibility in September - Etiwanda, 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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