Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The advent of September brings a subtle shift in temperature, with the average high moving from a tropical 89.2°F (31.8°C) in August to a warm 83.8°F (28.8°C). Penn Valley sees a consistent average low-temperature of 56.5°F (13.6°C) in September, indicating a substantial decrease from the day's temperature.Heat index
In September, the average heat index is calculated to be 82.4°F (28°C). Prolonged activity during exposure might result in a state of fatigue and cause heat cramps.In terms of the heat index, values are set with light wind and shade conditions in mind. Being under direct sunlight might amplify the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'real feel', evaluates the perceived heat by adding the effect of moisture in the air. The impression of weather on a person can be swayed by additional aspects, including metabolic variations, pregnancy, and activity levels. It is important to note that direct sunlight can intensify the weather impact, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold great significance to children. Youths are typically more endangered than adults since they usually sweat less. Their larger skin surface concerning their smaller bodies and higher heat production due to activity further adds to their vulnerability.
Humidity
The average relative humidity in September is 40%.Rainfall
In Penn Valley, during September, the rain falls for 2.3 days and regularly aggregates up to 0.28" (7mm) of precipitation. Throughout the year, there are 82 rainfall days, and 33.11" (841mm) of precipitation is accumulated.Snowfall
June through October are months without snowfall.Daylight
In September, the average length of the day is 12h and 26min.On the first day of September, 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.
Sunshine
In September, the average sunshine is 11.2h.UV index
The average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for ordinary individuals.Note: A maximum high daily UV index of 5 during September translates into the following directions:
Take precautions. Light skin individuals may get burned in less than 30 minutes. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot is September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
What is the average length of the day in September?
What time are sunrise and sunset in September in Penn Valley?
How long on average sun shines in September?
What is the UV index reading in September?
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).
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).
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).
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%).
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").
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).
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").
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).
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).
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).
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).
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).
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).
Penn Valley, California, USA
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