September weather forecast and climate
Norco, CA

Weather in September

The first month of the autumn, September, is still a hot month in Norco, California, with temperature in the range of an average high of 86.9°F (30.5°C) and an average low of 63.5°F (17.5°C).

Temperature

In Norco, California, the average high-temperature is practically the same as in August - a still hot 86.9°F (30.5°C). In Norco, in September, the average low-temperature is 63.5°F (17.5°C).

Heat index

The average heat index in September is appraised at a tropical 88.9°F (31.6°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', 'felt air temperature', 'real feel', or 'feels like', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. This effect is individual, with diverse people perceiving weather differently for numerous reasons (differences in body mass, height, and shape, clothing, wind), and activity. 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. 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

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

Rainfall

In Norco, California, during September, the rain falls for 2.5 days and regularly aggregates up to 0.12" (3mm) of precipitation. In Norco, during the entire year, the rain falls for 53.9 days and collects up to 8.86" (225mm) of precipitation.

Daylight

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

Sunshine

The average sunshine is 10.6h.

UV index

In Norco, California, the average daily maximum UV index is 6. A UV Index value of 6 to 7 symbolizes a high threat to health from unprotected exposure to the Sun's UV rays for the ordinary person.
Note: In September, the average maximum UV index of 6 translate into the following recommendations:
Take precautions against overexposure. Protection against sun damage is needed. 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. 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 Norco?

The average high-temperature, in September, in Norco, California, is 86.9°F (30.5°C), while the average low-temperature is 63.5°F (17.5°C). In September, the average heat index (a.k.a. 'feels like', 'real feel'), that combines air temperature and relative humidity, is estimated at 88.9°F (31.6°C).

What is the average humidity in September in Norco?

In September, the average relative humidity is 49%.

How many days does it rain in September in Norco?

In Norco, in September, during 2.5 rainfall days, 0.12" (3mm) of precipitation is typically accumulated.

What is the average length of the day in September in Norco?

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

How long on average sun shines in September in Norco?

In September, the average sunshine in Norco, California, is 10.6h.

What is the UV index reading in September in Norco?

The average daily maximum UV index in September is 6. A UV Index reading of 6 to 7 represents a high health risk from unsafe exposure to the Sun's UV rays.

Average temperature in September
Norco, CA

Average temperature in September - Norco, CA
  • Average high temperature in September: 86.9°F

The warmest month (with the highest average high temperature) is August (89.4°F).
The month with the lowest average high temperature is December (63.5°F).

  • Average low temperature in September: 63.5°F

The month with the highest average low temperature is August (65.8°F).
The coldest month (with the lowest average low temperature) is December (46.9°F).

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Average pressure in September
Norco, CA

Average pressure in September - Norco, 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 (29.87").

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Average wind speed in September
Norco, CA

Average wind speed in September - Norco, CA
  • Average wind speed in September: 4.3mph

The windiest months (with the highest average wind speed) are April and May (5.4mph).
The calmest month (with the lowest average wind speed) is September (4.3mph).

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Average humidity in September
Norco, CA

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

The month with the highest relative humidity is May (60%).
The month with the lowest relative humidity is November (48%).

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Average rainfall in September
Norco, CA

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

The wettest month (with the highest rainfall) is December (1.89").
The driest month (with the least rainfall) is June (0.04").

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Average rainfall days in September
Norco, CA

Average rainfall days in September - Norco, CA
  • Average rainfall days in September: 2.5 days

The month with the highest number of rainy days is March (8.2 days).
The month with the least rainy days is June (1.3 days).

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

Average daylight in September / Average sunshine in September - Norco, 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

Months with the most sunshine are July and August (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
Norco, CA

Average sunshine days in September - Norco, CA
  • Average sunshine days in September: 24.5 days

The month with the most sunshine days is June (27.1 days).
The month with the least sunshine days is February (20.8 days).

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Average UV index in September
Norco, CA

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

Months with the highest UV index are July and August (UV index 7).
Months with the lowest UV index are January, February, November and December (UV index 4).

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Average cloud cover in September
Norco, CA

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

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

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Average visibility in September
Norco, CA

Average visibility in September - Norco, 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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