September weather forecast
Blackhawk, CA

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Weather in September

The first month of the autumn, September, is also a moderately hot month in Blackhawk, California, with an average temperature fluctuating between 82°F (27.8°C) and 56.5°F (13.6°C).

Temperature

September's onset brings an average high-temperature of a still warm 82°F (27.8°C), showing a minute difference from August's 83.3°F (28.5°C). Blackhawk experiences a substantial decline from the daytime high temperatures in September, settling on an average low of 56.5°F (13.6°C).

Heat index

The heat index for September is estimated at 84.2°F (29°C). Persisting in activity during exposure could lead to weariness and subsequently to heat cramps.
It is important to note that the heat index values are for shaded areas and light wind scenarios. Exposing to direct sunshine may enhance heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'feels like', is what the temperature feels like to the human body when the air temperature is combined with the relative humidity. The individual's impression of temperature can be shaped by additional aspects such as metabolic variations, physical activity, and clothing. Awareness of direct sun exposure is crucial as it has the potential to heighten the weather's effects, pushing up the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely vital to babies and toddlers. Kids are usually more vulnerable than adults, given their lesser sweating ability. Along with their larger skin surface relative to their small stature and the excess heat due to their activity, their risk is amplified.

Humidity

The least humid month is September, with an average relative humidity of 57%.

Rainfall

In September, the rain falls for 1.8 days. Throughout September, 0.08" (2mm) of precipitation is accumulated. In Blackhawk, during the entire year, the rain falls for 67.2 days and collects up to 10.98" (279mm) of precipitation.

Daylight

In Blackhawk, the average length of the day in September is 12h and 25min.
On the first day of the month, sunrise is at 6:38 am and sunset at 7:36 pm. On the last day of September, sunrise is at 7:03 am and sunset at 6:51 pm PDT.

Sunshine

In Blackhawk, the average sunshine in September 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 unprotected exposure to Sun's UV rays for the ordinary person.
Note: The maximum UV index, 5 during September, leads to the following recommendations:
Undertake protective steps - Preventing sun damage is advised. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes.
Updated: Aug 19, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Blackhawk in September?

An average high-temperature, in September, in Blackhawk, is 82°F (27.8°C) and the average low-temperature is 56.5°F (13.6°C). The average heat index (a.k.a. 'real feel', 'apparent temperature'), which combines relative humidity and air temperature, in September is estimated at 84.2°F (29°C).

What is the least humid month?

With an average relative humidity of 57%, September is the least humid month in Blackhawk.

What is the average humidity in September?

In Blackhawk, the average relative humidity in September is 57%.

How many days does it rain in September?

In Blackhawk, in September, it is raining for 1.8 days, with typically 0.08" (2mm) of accumulated precipitation.

What is the average length of the day in September?

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

When are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:38 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 7:03 am and sunset at 6:51 pm PDT.

How long on average sun shines in September in Blackhawk?

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

What is the UV index reading in September?

In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a medium health risk from unsafe 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
Blackhawk, CA

Average temperature in September - Blackhawk, CA
  • Average high temperature in September: 82°F

The warmest month (with the highest average high temperature) is July (83.7°F).
The month with the lowest average high temperature is December (55.9°F).

  • Average low temperature in September: 56.5°F

The month with the highest average low temperature is September (56.5°F).
The coldest month (with the lowest average low temperature) is December (42.1°F).

Average pressure in September
Blackhawk, CA

Average pressure in September - Blackhawk, 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).

Average wind speed in September
Blackhawk, CA

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

The windiest month (with the highest average wind speed) is May (6.7mph).
The calmest month (with the lowest average wind speed) is November (4.2mph).

Average humidity in September
Blackhawk, CA

Average humidity in September - Blackhawk, CA
  • Average humidity in September: 57%

The month with the highest relative humidity is March (74%).
The month with the lowest relative humidity is September (57%).

Average rainfall in September
Blackhawk, CA

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

The wettest month (with the highest rainfall) is February (2.28").
The driest month (with the least rainfall) is July (0").

Average rainfall days in September
Blackhawk, CA

Average rainfall days in September - Blackhawk, CA
  • Average rainfall days in September: 1.8 days

The month with the highest number of rainy days is March (12.6 days).
The month with the least rainy days is August (0.6 days).

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

Average daylight in September / Average sunshine in September - Blackhawk, 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: 5h and 48min).

Average sunshine days in September
Blackhawk, CA

Average sunshine days in September - Blackhawk, CA
  • Average sunshine days in September: 27.5 days

The month with the most sunshine days is July (29.9 days).
The month with the least sunshine days is March (17.5 days).

Average UV index in September
Blackhawk, CA

Average UV index in September - Blackhawk, 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).

Average cloud cover in September
Blackhawk, CA

Average cloud cover in September - Blackhawk, CA
  • Average cloud cover in September: 10

The month with the most cloud cover is March (Cloud cover 36).
The month with the least cloud cover is July (Cloud cover 6).

Average visibility in September
Blackhawk, CA

Average visibility in September - Blackhawk, 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).

Blackhawk, California, USA

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