September weather forecast
Penn Valley, CA

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Weather in September

The first month of the autumn, September, is still a warm month in Penn Valley, California, with an average temperature varying between 56.5°F (13.6°C) and 83.8°F (28.8°C).

Temperature

With September's onset, the weather reveals a slight temperature decrease, transitioning from a tropical 89.2°F (31.8°C) in August to a moderately hot 83.8°F (28.8°C). Penn Valley's September nights see a large temperature deviation, with temperatures resting at a low of 56.5°F (13.6°C).

Heat index

Throughout September, the heat index is computed to be 82.4°F (28°C). If one continues to be active during enduring exposure, it could result in fatigue and heat cramps.
The standards for the heat index are set for locations in shade and under light breezes. The heat index could see an increase by 15 Fahrenheit (8 Celsius) degrees under direct sunshine.
Note: The heat index, also known as 'felt air temperature' or 'real feel', determines the feeling of heat when you account for the relative humidity. The individual's impression of temperature can be shaped by additional aspects such as metabolic variations, physical activity, and clothing. In the direct sunlight, the weather's impact can be amplified, possibly boosting the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to babies and toddlers. Young ones regularly neglect the requirement for rest and fluid replenishment. Thirst is a late stage of dehydration - so, it is necessary to keep hydrated, particularly during extended periods of physical exertion.

Humidity

The average relative humidity in September is 40%.

Rainfall

In Penn Valley, in September, during 2.3 rainfall days, 0.28" (7mm) of precipitation is typically accumulated. In Penn Valley, during the entire year, the rain falls for 82 days and collects up to 33.11" (841mm) of precipitation.

Snowfall

June through October are months without snowfall.

Daylight

In Penn Valley, the average length of the day in September is 12h and 26min.
On the first day of the month, sunrise is at 6:34 am and sunset at 7:34 pm. On the last day of September, sunrise is at 7:00 am and sunset at 6:48 pm PDT.

Sunshine

The average sunshine in September in Penn Valley, California, is 11.2h.

UV index

The average daily maximum UV index in September in Penn Valley is 5. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.
Note: A maximum daily UV index of 5 during September morphs into the following directions:
Undertake precautions - Guarding against sun damage is counselled. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
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Frequently asked questions

Is it hot in Penn Valley during September?

September temperatures in Penn Valley, California, vary between a high-temperature of 83.8°F (28.8°C) and a low-temperature of 56.5°F (13.6°C). The average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), which combines air temperature and relative humidity, in September is computed to be 82.4°F (28°C).

What is the average humidity in September in Penn Valley?

The average relative humidity in September is 40%.

How many days does it rain in September in Penn Valley?

In Penn Valley, California, in September, during 2.3 rainfall days, 0.28" (7mm) of precipitation is typically accumulated.

When it does not snow in Penn Valley?

In Penn Valley, California, snow does not fall in June through October.

What is the average length of the day in September in Penn Valley?

The average day length in September in Penn Valley, California, is 12h and 26min.

When is the sunrise / sunset in September in Penn Valley?

On the first day of September in Penn Valley, California, sunrise is at 6:34 am and sunset at 7:34 pm. On the last day of the month, sunrise is at 7:00 am and sunset at 6:48 pm PDT.

How long on average sun shines in September in Penn Valley?

The average sunshine duration in September in Penn Valley, California, is 11.2h.

How high is the UV index in September in Penn Valley?

In Penn Valley, California, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium health risk from unprotected exposure to UV radiation.
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
Penn Valley, CA

Average temperature in September - Penn Valley, CA
  • Average high temperature in September: 83.8°F

The warmest month (with the highest average high temperature) is July (90.1°F).
The month with the lowest average high temperature is December (51.3°F).

  • Average low temperature in September: 56.5°F

The month with the highest average low temperature is July (60.1°F).
The coldest month (with the lowest average low temperature) is December (37.2°F).

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Average pressure in September
Penn Valley, CA

Average pressure in September - Penn Valley, CA
  • Average pressure in September: 29.92"Hg

The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

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Average wind speed in September
Penn Valley, CA

Average wind speed in September - Penn Valley, CA
  • Average wind speed in September: 5.2mph

The windiest month (with the highest average wind speed) is February (6mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).

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Average humidity in September
Penn Valley, CA

Average humidity in September - Penn Valley, CA
  • Average humidity in September: 40%

The month with the highest relative humidity is March (75%).
The month with the lowest relative humidity is July (37%).

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Average rainfall in September
Penn Valley, CA

Average rainfall in September - Penn Valley, CA
  • Average rainfall in September: 0.28"

The wettest month (with the highest rainfall) is March (6.57").
The driest months (with the least rainfall) are July and August (0.04").

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Average rainfall days in September
Penn Valley, CA

Average rainfall days in September - Penn Valley, CA
  • Average rainfall days in September: 2.3 days

The month with the highest number of rainy days is March (15.1 days).
The month with the least rainy days is July (1.1 days).

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Average snowfall in September
Penn Valley, CA

Average snowfall in September - Penn Valley, CA
  • Average snowfall in September: 0"

The month with the highest snowfall is February (6.42").
The months with the least snowfall are June, July, August, September and October (0").

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Average snowfall days in September
Penn Valley, CA

Average snowfall days in September - Penn Valley, CA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is March (2.4 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

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Average daylight in September /
Average sunshine in September
Penn Valley, CA

Average daylight in September / Average sunshine in September - Penn Valley, 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: 11h and 1min

The month with the most sunshine is July (Average sunshine: 12h and 12min).
The month with the least sunshine is January (Average sunshine: 5h and 42min).

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Average sunshine days in September
Penn Valley, CA

Average sunshine days in September - Penn Valley, CA
  • Average sunshine days in September: 26.9 days

The month with the most sunshine days is July (29.8 days).
The month with the least sunshine days is March (14.8 days).

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Average UV index in September
Penn Valley, CA

Average UV index in September - Penn Valley, CA
  • Average UV index in September: 5

The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is November (UV index 2).

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Average cloud cover in September
Penn Valley, CA

Average cloud cover in September - Penn Valley, CA
  • Average cloud cover in September: 8

The month with the most cloud cover is March (Cloud cover 41).
The month with the least cloud cover is July (Cloud cover 4).

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Average visibility in September
Penn Valley, CA

Average visibility in September - Penn Valley, CA
  • Average visibility in September: 6mi

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

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Penn Valley, California, USA

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