September weather forecast and climate
Calpella, CA

Weather in September

The first month of the autumn, September, is also a moderately hot month in Calpella, California, with average temperature varying between 80.8°F (27.1°C) and 51.4°F (10.8°C).

Temperature

In Calpella, the average high-temperature is essentially the same as in August - a still moderately hot 80.8°F (27.1°C). The average low-temperature, in Calpella, is 51.4°F (10.8°C).

Heat index

The average heat index is calculated to 82.6°F (28.1°C). Constant exposure and activity lead to possible fatigue. Prolonged exercise 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', 'real feel', 'felt air temperature', or 'feels like', combines air temperature and relative humidity to represent a human perceived temperature equivalent. This effect is individual, with diverse people perceiving weather differently for numerous reasons (metabolic differences, pregnancy, clothing), 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 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

Months with the lowest humidity in Calpella are July and September, with an average relative humidity of 58%.

Rainfall

In Calpella, in September, during 2.5 rainfall days, 0.2" (5mm) of precipitation is typically accumulated. In Calpella, during the entire year, the rain falls for 83.3 days and collects up to 17.72" (450mm) of precipitation.

Snowfall

In Calpella, California, 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 Calpella is 10.9h.

UV index

The average daily maximum UV index in Calpella is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from unsafe exposure to the UV radiation for the ordinary person.
Note: The daily maximum UV index of 4 in September interpret into the following advice:
Take precautions - Protection against sun damage is advised. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. 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 Calpella?

In Calpella, in September, the average high-temperature is 80.8°F (27.1°C), and the average low-temperature is 51.4°F (10.8°C). In September, the average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), that represents influence of the relative humidity to air temperaure, is evaluated at 82.6°F (28.1°C).

What is the least humid month in Calpella?

July and September, with an average relative humidity of 58%, are the least humid months.

What is the average humidity in September in Calpella?

In Calpella, the average relative humidity in September is 58%.

How many days does it rain in September in Calpella?

In Calpella, California, in September, it is raining for 2.5 days, with typically 0.2" (5mm) of accumulated precipitation.

When it does not snow in Calpella?

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

How many hours of daylight does Calpella have in September?

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

How many hours of sunshine does Calpella have in September?

In September, the average sunshine in Calpella is 10.9h.

What is the UV index intensity in September in Calpella?

In Calpella, California, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health risk from unprotected exposure to the UV radiation.

Average temperature in September
Calpella, CA

Average temperature in September - Calpella, CA
  • Average high temperature in September: 80.8°F

The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is December (53.6°F).

  • Average low temperature in September: 51.4°F

The month with the highest average low temperature is July (53.6°F).
The coldest month (with the lowest average low temperature) is December (37.4°F).

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Average pressure in September
Calpella, CA

Average pressure in September - Calpella, CA
  • Average pressure in September: 29.92"

The month with the highest atmospheric pressure is January (30.13").
Months with the lowest atmospheric pressure are June, August and September (29.92").

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Average wind speed in September
Calpella, CA

Average wind speed in September - Calpella, CA
  • Average wind speed in September: 4.4mph

The windiest months (with the highest average wind speed) are April, May and June (5.5mph).
The calmest month (with the lowest average wind speed) is November (4.2mph).

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Average humidity in September
Calpella, CA

Average humidity in September - Calpella, CA
  • Average humidity in September: 58%

The month with the highest relative humidity is March (79%).
Months with the lowest relative humidity are July and September (58%).

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Average rainfall in September
Calpella, CA

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

The wettest months (with the highest rainfall) are February and December (3.11").
The driest months (with the least rainfall) are July and August (0.08").

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Average rainfall days in September
Calpella, CA

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

The month with the highest number of rainy days is March (14.3 days).
The month with the least rainy days is August (1.3 days).

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Average snowfall in September
Calpella, CA

Average snowfall in September - Calpella, 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
Calpella, CA

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

The month with the highest number of snowfall days is February (0.3 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
Calpella, CA

Average daylight in September / Average sunshine in September - Calpella, CA
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.9h).
The month with the shortest days is December (Average daylight: 9.5h).

  • Average sunshine in September: 10.9h

The month with the most sunshine is July (Average sunshine: 12h).
The month with the least sunshine is December (Average sunshine: 5.3h).

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Average sunshine days in September
Calpella, CA

Average sunshine days in September - Calpella, CA
  • Average sunshine days in September: 26.9 days

The month with the most sunshine days is July (28.5 days).
The month with the least sunshine days is March (15.9 days).

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Average UV index in September
Calpella, CA

Average UV index in September - Calpella, CA
  • Average UV index in September: 4

Months with the highest UV index are June and July (UV index 6).
Months with the lowest UV index are February and November (UV index 2).

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Average cloud cover in September
Calpella, CA

Average cloud cover in September - Calpella, CA
  • Average cloud cover in September: 11

The month with the most cloud cover is March (Cloud cover 45).
The month with the least cloud cover is August (Cloud cover 6).

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Average visibility in September
Calpella, CA

Average visibility in September - Calpella, CA
  • Average visibility in September: 6mi

Months with the highest visibility are February, April, May, June, July, August, September, October and November (6mi).
Months with the lowest visibility are January, March and December (5mi).

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