September weather forecast
Calpella, CA

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Weather in September

The first month of the autumn, September, is still a warm month in Calpella, California, with an average temperature ranging between max 80.8°F (27.1°C) and min 51.4°F (10.8°C).

Temperature

The advent of September reveals an average high-temperature of a still moderately hot 80.8°F (27.1°C), showing minimal difference from the prior month. Calpella sees a large disparity in day to night temperatures in September, with the night temperature dropping to an average of 51.4°F (10.8°C).

Heat index

September's average heat index is calculated to be 82.4°F (28°C). If one sustains activity during exposure, it could lead to a sense of fatigue, with a chance of heat cramps.
Be advised, the heat index considers values for conditions in shade and with a light breeze. Direct sunlight can potentially boost the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', represents the fusion of temperature and moisture in the air to suggest how warm it feels. Factors such as metabolic variations, being pregnant, and physical activity can impact an individual's weather perception. Awareness is key; direct sunlight can enhance the weather's impact, possibly boosting the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely vital to babies and toddlers. Children frequently do not comprehend the need for rest and hydration. Thirst is an advanced stage of dehydration - staying hydrated, especially during extended physical exercises, is essential.

Humidity

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

Rainfall

In Calpella, during September, the rain falls for 2.5 days and regularly aggregates up to 0.2" (5mm) of precipitation. Throughout the year, there are 83.3 rainfall days, and 17.72" (450mm) of precipitation is accumulated.

Snowfall

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

Daylight

The average length of the day in September is 12h and 26min.
On the first day of September, sunrise is at 6:42 am and sunset at 7:42 pm. On the last day of the month, sunrise is at 7:08 am and sunset at 6:56 pm PDT.

Sunshine

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

UV index

In Calpella, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for the average person.
Note: The maximum daily UV index of 4 in September converts into the following recommendations:
Act with care - Obligation to protect against skin and eye damage is highlighted. Around midday, solar radiation is most harmful; hence, exposure should be limited. During bright days, sunglasses that offer UVA and UVB defense are recommended.
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Frequently asked questions

What is the usual temperature for Calpella in September?

The average high-temperature, in September, in Calpella, is 80.8°F (27.1°C), while the average low-temperature is 51.4°F (10.8°C). The average heat index (a.k.a. 'real feel', 'feels like'), which takes the relative humidity and factors it into the air temperature reading, in September is calculated to be 82.4°F (28°C).

What are the least humid months 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 September, the average relative humidity is 58%.

How much does it rain in Calpella in September?

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

When it does not snow in Calpella?

January, March through December are months without snowfall.

How many hours of daylight does Calpella have in September?

In Calpella, the average day length in September is 12h and 26min.

What time are sunrise and sunset in September in Calpella?

On the first day of September in Calpella, California, sunrise is at 6:42 am and sunset at 7:42 pm. On the last day of the month, sunrise is at 7:08 am and sunset at 6:56 pm PDT.

How long on average sun shines in September in Calpella?

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

What is the UV index reading in September in Calpella?

In Calpella, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium hazard to health from unsafe exposure to Sun's UV rays.
Average max. wind speed
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

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"Hg

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

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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%).
The 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").
The 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).
The 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: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).

  • Average sunshine in September: 10h and 5min

The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).

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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

The months with the highest UV index are June and July (UV index 6).
The 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

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

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Calpella, California, USA

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