September weather forecast and climate
Duarte, CA

Weather in September

September, the first month of the autumn, in Duarte, is still a warm month, with average temperature fluctuating between 85.5°F (29.7°C) and 62.8°F (17.1°C).

Temperature

In September, the average high-temperature is essentially the same as in August - a warm 85.5°F (29.7°C). In Duarte, the average low-temperature is 62.8°F (17.1°C).

Heat index

In September, the average heat index is calculated to a hot 86.5°F (30.3°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. With the 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', 'real feel', 'felt air temperature', or 'apparent temperature', is a measure of how hot it feels when the actual air humidity is factored in. This effect is subjective, depending on the activity and individual's heat perception influenced by various reasons (pregnancy, wind, metabolic differences). Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index 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 Duarte, the average relative humidity is 48%.

Rainfall

In September, the rain falls for 2.6 days. Throughout September, 0.12" (3mm) of precipitation is accumulated. In Duarte, during the entire year, the rain falls for 50.9 days and collects up to 8.46" (215mm) of precipitation.

Daylight

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

Sunshine

In Duarte, the average sunshine in September is 10.8h.

UV index

June through September, with an average maximum UV index of 6, are months with the highest UV index in Duarte. A UV Index of 6 to 7 symbolizes a high threat to health from unsafe exposure to the UV radiation for the average person.
Note: The daily maximum UV index of 6 in September interpret into the following advice:
Take precautions and utilize sun safety practices. Protection against the skin and eye damage is required. 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 Duarte?

In September, the average high-temperature is 85.5°F (29.7°C), and the average low-temperature is 62.8°F (17.1°C). The average heat index (a.k.a. 'feels like', 'real feel'), that combines relative humidity and air temperature, in September is evaluated at 86.5°F (30.3°C).

What is the average humidity in September in Duarte?

The average relative humidity in September in Duarte is 48%.

How much does it rain in Duarte in September?

In Duarte, in September, during 2.6 rainfall days, 0.12" (3mm) of precipitation is typically accumulated.

How many hours of daylight does Duarte have in September?

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

How long on average sun shines in September in Duarte?

In September, the average sunshine in Duarte, California, is 10.8h.

When is the highest UV index in Duarte?

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

What is the UV index intensity in September in Duarte?

The average daily maximum UV index in September in Duarte is 6. A UV Index value of 6 to 7 symbolizes a high health risk from the exposure to the Sun's UV radiation.

Average temperature in September
Duarte, CA

Average temperature in September - Duarte, CA
  • Average high temperature in September: 85.5°F

The warmest month (with the highest average high temperature) is August (88.2°F).
The month with the lowest average high temperature is December (61.7°F).

  • Average low temperature in September: 62.8°F

The month with the highest average low temperature is August (64.8°F).
The coldest month (with the lowest average low temperature) is December (45.7°F).

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Average pressure in September
Duarte, CA

Average pressure in September - Duarte, CA
  • Average pressure in September: 29.89"

The month with the highest atmospheric pressure is January (30.11").
The month with the lowest atmospheric pressure is June (29.88").

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Average wind speed in September
Duarte, CA

Average wind speed in September - Duarte, 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
Duarte, CA

Average humidity in September - Duarte, CA
  • Average humidity in September: 48%

Months with the highest relative humidity are March and May (56%).
The month with the lowest relative humidity is November (46%).

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Average rainfall in September
Duarte, CA

Average rainfall in September - Duarte, CA
  • Average rainfall in September: 0.12"

The wettest months (with the highest rainfall) are February and December (1.77").
The driest month (with the least rainfall) is June (0.04").

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Average rainfall days in September
Duarte, CA

Average rainfall days in September - Duarte, CA
  • Average rainfall days in September: 2.6 days

The month with the highest number of rainy days is March (7.4 days).
The month with the least rainy days is June (1.1 days).

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

Average daylight in September / Average sunshine in September - Duarte, 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: 10.8h

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

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Average sunshine days in September
Duarte, CA

Average sunshine days in September - Duarte, CA
  • Average sunshine days in September: 26.2 days

The month with the most sunshine days is June (28.3 days).
The month with the least sunshine days is February (21 days).

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Average UV index in September
Duarte, CA

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

Months with the highest UV index are June, July, August and September (UV index 6).
The month with the lowest UV index is December (UV index 3).

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Average cloud cover in September
Duarte, CA

Average cloud cover in September - Duarte, CA
  • Average cloud cover in September: 7

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
Duarte, CA

Average visibility in September - Duarte, 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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