September weather forecast
Blackhawk, CA

Share

Weather in September

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

Temperature

As Blackhawk welcomes September, the average high-temperature is noted at a still moderately hot 82°F (27.8°C), closely aligning with the preceding month. In September, Blackhawk experiences a significant drop from daily zeniths to an average nighttime temperature of 56.5°F (13.6°C).

Heat index

The heat index value during September is calculated to be 84.2°F (29°C). Unrelenting activity during exposure could cause fatigue and potentially lead to heat cramps.
Be aware that heat index ratings are designed for shaded locations and minor breezes. Exposing to direct sunshine may enhance heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', is an aggregate value of air's warmth and moisture to show the human-felt temperature. One's perception of temperature is subjective, varying based on their activity and individual heat perception, influenced by factors like wind, clothing, and metabolic variations. Being aware that direct sunlight can impact the felt heat might mean an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Young ones often underestimate the need for rest and rehydration. Thirst appears late in dehydration - hence, it is important to keep hydrated, particularly during prolonged physical activities.

Humidity

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

Rainfall

In September, in Blackhawk, 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

The average length of the day in September in Blackhawk 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, in Blackhawk, sunrise is at 7:03 am and sunset at 6:51 pm PDT.

Sunshine

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

UV index

The average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate threat to health 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:
Take necessary precautions - Suggestions to elude sunburn are provided. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage.
[Resources]

Frequently asked questions

What are September temperatures in Blackhawk?

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', 'feels like'), which combines air temperature and relative humidity, in September is calculated to be 84.2°F (29°C).

What is the least humid month in Blackhawk?

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

What is the average humidity in September in Blackhawk?

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

How much does it rain in Blackhawk in September?

In Blackhawk, during September, the rain falls for 1.8 days and regularly aggregates up to 0.08" (2mm) of precipitation.

How many hours of daylight does Blackhawk have in September?

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

When is the sunrise / sunset in September in Blackhawk?

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, in Blackhawk, sunrise is at 7:03 am and sunset at 6:51 pm PDT.

How long on average sun shines in September in Blackhawk?

In September, the average sunshine duration is 11.2h.

What is the UV index reading in September in Blackhawk?

In Blackhawk, California, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate health threat 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
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).

[Resources]

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).

[Resources]

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).

[Resources]

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%).

[Resources]

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").

[Resources]

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).

[Resources]

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).

[Resources]

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).

[Resources]

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).

[Resources]

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).

[Resources]

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).

[Resources]

Blackhawk, California, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location