September weather forecast
Sunol, CA

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Weather in September

September, the first month of the autumn in Sunol, is still a warm month, with an average temperature varying between 82°F (27.8°C) and 56.3°F (13.5°C).

Temperature

The shift to September signals an average high-temperature of a still moderately hot 82°F (27.8°C), subtly varied from August's 84.7°F (29.3°C). Sunol reports a steady low-temperature average of 56.3°F (13.5°C) throughout September, revealing a large deviation from the daytime high.

Heat index

The average heat index in September is estimated at 84.2°F (29°C). If one remains active during constant exposure, it might cause exhaustion and heat cramps.
It is noted that heat index values are ascertained for locations in the shade and with gentle breezes. Direct sunlight can cause a surge in the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', reflects the blend of air temperature and relative humidity to give a temperature impression. One's perception of temperature can vary depending on physical activity and individual heat sensitivity, influenced by factors like wind, attire, and metabolic variations. 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 largely significant for babies and toddlers. Kids frequently fail to realize the necessity for resting and hydrating. Thirst is an advanced indication of dehydration - hence, maintaining hydration, especially during extended physical activities, becomes essential.

Humidity

July and September, with an average relative humidity of 56%, are the least humid months.

Rainfall

In Sunol, in September, during 2.3 rainfall days, 0.12" (3mm) of precipitation is typically accumulated. Throughout the year, in Sunol, California, there are 70.2 rainfall days, and 10.98" (279mm) of precipitation is accumulated.

Daylight

In Sunol, the average length of the day in September is 12h and 25min.
On the first day of September, sunrise is at 6:38 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 7:02 am and sunset at 6:51 pm PDT.

Sunshine

In September, the average sunshine in Sunol, California, is 11.2h.

UV index

In September, the average daily maximum UV index in Sunol is 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for the ordinary person.
Note: A daily high UV index of 5 in September leads to these guidelines:
Preventative actions are necessary - Suggestions to safeguard against sun damage are in order. Direct Sun exposure should be minimized especially during midday when radiation is most intense. A hat with a broad brim is indispensable, filtering out up to half of UV rays.
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Frequently asked questions

What are September temperatures in Sunol?

In September, in Sunol, the average high-temperature is 82°F (27.8°C), and the average low-temperature is 56.3°F (13.5°C). In September, the average heat index (a.k.a. 'feels like', 'real feel'), which combines air temperature and relative humidity, is estimated at 84.2°F (29°C).

What are the least humid months in Sunol?

July and September, with an average relative humidity of 56%, are the least humid months in Sunol, California.

What is the average humidity in September in Sunol?

The average relative humidity in September in Sunol, California, is 56%.

How many days does it rain in September in Sunol?

In Sunol, California, in September, during 2.3 rainfall days, 0.12" (3mm) of precipitation is typically accumulated.

What is the average length of the day in September in Sunol?

The average day length in September is 12h and 25min.

When are sunrise and sunset in September in Sunol?

On the first day of September in Sunol, sunrise is at 6:38 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 7:02 am and sunset at 6:51 pm PDT.

How long on average sun shines in September in Sunol?

In September, the average sunshine duration in Sunol, California, is 11.2h.

How high is the UV index in September in Sunol?

The average daily maximum UV index in September in Sunol is 5. A UV Index value of 3 to 5 symbolizes a moderate vulnerability from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Sunol, CA

Average temperature in September - Sunol, CA
  • Average high temperature in September: 82°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 (55°F).

  • Average low temperature in September: 56.3°F

The month with the highest average low temperature is August (56.7°F).
The coldest month (with the lowest average low temperature) is January (41.5°F).

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Average pressure in September
Sunol, CA

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

The month with the highest atmospheric pressure is January (30.14"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
Sunol, CA

Average wind speed in September - Sunol, CA
  • Average wind speed in September: 5mph

The windiest month (with the highest average wind speed) is May (6.3mph).
The calmest month (with the lowest average wind speed) is November (4.2mph).

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Average humidity in September
Sunol, CA

Average humidity in September - Sunol, CA
  • Average humidity in September: 56%

The month with the highest relative humidity is March (74%).
The months with the lowest relative humidity are July and September (56%).

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Average rainfall in September
Sunol, CA

Average rainfall in September - Sunol, CA
  • Average rainfall in September: 0.12"

The wettest month (with the highest rainfall) is February (2.05").
The driest months (with the least rainfall) are July and August (0.04").

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Average rainfall days in September
Sunol, CA

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

The month with the highest number of rainy days is March (12.4 days).
The month with the least rainy days is August (0.9 days).

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

Average daylight in September / Average sunshine in September - Sunol, 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 1min

The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 0min).

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Average sunshine days in September
Sunol, CA

Average sunshine days in September - Sunol, CA
  • Average sunshine days in September: 27 days

The month with the most sunshine days is August (29 days).
The month with the least sunshine days is March (17.6 days).

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Average UV index in September
Sunol, CA

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

The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).

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Average cloud cover in September
Sunol, CA

Average cloud cover in September - Sunol, CA
  • Average cloud cover in September: 9

The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 5).

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Average visibility in September
Sunol, CA

Average visibility in September - Sunol, 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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Sunol, California, USA

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