September weather forecast
Piedmont, CA

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Weather in September

The first month of the autumn, September, is also a moderately hot month in Piedmont, California, with temperature in the range of an average high of 76.6°F (24.8°C) and an average low of 56.8°F (13.8°C).

Temperature

In Piedmont, the month of September registers the highest temperatures, averaging 76.6°F (24.8°C) at the peak and 56.8°F (13.8°C) at the lowest.

Humidity

The average relative humidity in September is 65%.

Rainfall

The months with the least rainfall are June through September Rain falls for 2.3 days and accumulates 0.08" (2mm) of rain.

Daylight

The average length of the day in September is 12h and 25min.
On the first day of September, sunrise is at 6:39 am and sunset at 7:37 pm. On the last day of the month, sunrise is at 7:04 am and sunset at 6:52 pm PDT.

Sunshine

In Piedmont, California, the average sunshine in September is 11h.

UV index

April through September, with an average maximum UV index of 5, are months with the highest UV index in Piedmont. A UV Index estimate of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for the average person.
Note: In September, a daily UV index of 5 turns into the following recommendations:
Ensure safety - Recommendations to avert sunburn are presented. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. Experience reduced UV exposure by about half when donning a wide-brim hat.

Frequently asked questions

What are the warmest months?

September temperatures tend to peak at an average high of 76.6°F (24.8°C) and dip to a low of 56.8°F (13.8°C).

What are September temperatures?

Piedmont in September has an average high-temperature of 76.6°F (24.8°C) and an average low-temperature of 56.8°F (13.8°C).

What is the average humidity in September?

In September, the average relative humidity is 65%.

What is the driest month?

June through September are months with the least rain when the rain falls for 2.3 days and typically aggregates up to 0.08" (2mm) of rain.

How much does it rain in September?

In Piedmont, in September, during 2.3 rainfall days, 0.08" (2mm) of precipitation is typically accumulated.

How many hours of daylight does Piedmont have in September?

In September, the average day length is 12h and 25min.

When is the sunrise / sunset in September?

On the first day of September, sunrise is at 6:39 am and sunset at 7:37 pm. On the last day of the month, sunrise is at 7:04 am and sunset at 6:52 pm PDT.

How many hours of sunshine does Piedmont have in September?

In Piedmont, the average sunshine duration in September is 11h.

When is the highest UV index?

April through September, with an average maximum UV index of 5, are months with the highest UV index.

How high is the UV index in September?

In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a moderate health threat from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Piedmont, CA

Average temperature in September - Piedmont, CA
  • Average high temperature in September: 76.6°F

The warmest month (with the highest average high temperature) is September (76.6°F).
The month with the lowest average high temperature is December (55.4°F).

  • Average low temperature in September: 56.8°F

The month with the highest average low temperature is September (56.8°F).
The coldest month (with the lowest average low temperature) is January (44.2°F).

Average pressure in September
Piedmont, CA

Average pressure in September - Piedmont, 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).

Average wind speed in September
Piedmont, CA

Average wind speed in September - Piedmont, CA
  • Average wind speed in September: 5.6mph

The windiest month (with the highest average wind speed) is May (7.3mph).
The calmest month (with the lowest average wind speed) is November (5mph).

Average humidity in September
Piedmont, CA

Average humidity in September - Piedmont, CA
  • Average humidity in September: 65%

The month with the highest relative humidity is March (75%).
The month with the lowest relative humidity is October (64%).

Average rainfall in September
Piedmont, CA

Average rainfall in September - Piedmont, CA
  • Average rainfall in September: 0.08"

The wettest month (with the highest rainfall) is February (1.1").
The driest months (with the least rainfall) are June, July, August and September (0.08").

Average rainfall days in September
Piedmont, CA

Average rainfall days in September - Piedmont, CA
  • Average rainfall days in September: 2.3 days

The month with the highest number of rainy days is March (8.7 days).
The month with the least rainy days is August (1.5 days).

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

Average daylight in September / Average sunshine in September - Piedmont, CA
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).

  • Average sunshine in September: 11h and 0min

The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).

Average sunshine days in September
Piedmont, CA

Average sunshine days in September - Piedmont, CA
  • Average sunshine days in September: 24.9 days

The month with the most sunshine days is October (26 days).
The month with the least sunshine days is February (20.5 days).

Average UV index in September
Piedmont, CA

Average UV index in September - Piedmont, CA
  • Average UV index in September: 5

The months with the highest UV index are April, May, June, July, August and September (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 3).

Average cloud cover in September
Piedmont, CA

Average cloud cover in September - Piedmont, CA
  • Average cloud cover in September: 13

The month with the most cloud cover is March (Cloud cover 36).
The month with the least cloud cover is July (Cloud cover 11).

Average visibility in September
Piedmont, CA

Average visibility in September - Piedmont, 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).

Piedmont, California, USA

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