September weather forecast
Volcano, CA

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Weather in September

September, the first month of the autumn in Volcano, is also a moderately hot month, with an average temperature varying between 57°F (13.9°C) and 85.1°F (29.5°C).

Temperature

The shift from August to September is characterized by an average high-temperature of a warm 85.1°F (29.5°C), not significantly different from the 90.1°F (32.3°C) of August. Volcano undergoes a major shift from daytime highs, averaging a mild 57°F (13.9°C) during the night in September.

Heat index

The average heat index in September is evaluated at 84.2°F (29°C). Constant exposure and activity lead to possible fatigue. Prolonged exercise may result in heat cramps.
Heat index values are typically calculated for conditions of shade and a light breeze. Heat index values may rise by up to 15 Fahrenheit (8 Celsius) degrees when exposed to direct sunlight.
Note: The heat index, also known as 'apparent temperature' or 'real feel', is an indicator that blends the effects of temperature and humidity to depict perceived warmth. Factors such as metabolic variations, being pregnant, and physical activity can impact an individual's weather perception. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for children. Children usually face more risks than adults as their ability to sweat is less. Additionally, their larger skin surface in relation to their petite bodies and higher heat output due to their activities increases their vulnerability.

Humidity

In Volcano, the average relative humidity in September is 42%.

Rainfall

In September, the rain falls for 3 days. Throughout September, 0.24" (6mm) of precipitation is accumulated. In Volcano, during the entire year, the rain falls for 81.8 days and collects up to 23.39" (594mm) of precipitation.

Snowfall

January, April through October are months without snowfall.

Daylight

In September, the average length of the day is 12h and 25min.
On the first day of September, sunrise is at 6:32 am and sunset at 7:31 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 6:46 pm PDT.

Sunshine

In Volcano, California, the average sunshine in September is 11.3h.

UV index

In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for average individuals.
Note: A maximum high UV index of 5 in September translates into the following recommendations:
Take necessary precautions - Defending against sun damage is advocated. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation.

Frequently asked questions

Is it hot during September?

Volcano in September has an average high-temperature of 85.1°F (29.5°C) and an average low-temperature of 57°F (13.9°C). The average heat index (a.k.a. 'feels like', 'real feel'), which calculates the temperature value influenced by the moisture in the air, in September is evaluated at 84.2°F (29°C).

What is the average humidity in September?

The average relative humidity in September is 42%.

How many days does it rain in September?

In Volcano, in September, during 3 rainfall days, 0.24" (6mm) of precipitation is typically accumulated.

When it does not snow?

In Volcano, snow does not fall in January, April through October.

How many hours of daylight does Volcano have in September?

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

When are sunrise and sunset in September?

On the first day of September, sunrise is at 6:32 am and sunset at 7:31 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 6:46 pm PDT.

How long on average sun shines in September?

In Volcano, the average sunshine duration in September is 11.3h.

What is the UV index reading in September in Volcano?

The average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate vulnerability from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Volcano, CA

Average temperature in September - Volcano, CA
  • Average high temperature in September: 85.1°F

The warmest month (with the highest average high temperature) is July (91°F).
The month with the lowest average high temperature is December (52.9°F).

  • Average low temperature in September: 57°F

The month with the highest average low temperature is July (59°F).
The coldest month (with the lowest average low temperature) is December (37.9°F).

Average pressure in September
Volcano, CA

Average pressure in September - Volcano, CA
  • Average pressure in September: 29.93"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

Average wind speed in September
Volcano, CA

Average wind speed in September - Volcano, CA
  • Average wind speed in September: 4mph

The windiest month (with the highest average wind speed) is February (5.7mph).
The calmest month (with the lowest average wind speed) is August (3.8mph).

Average humidity in September
Volcano, CA

Average humidity in September - Volcano, CA
  • Average humidity in September: 42%

The month with the highest relative humidity is March (74%).
The month with the lowest relative humidity is July (40%).

Average rainfall in September
Volcano, CA

Average rainfall in September - Volcano, CA
  • Average rainfall in September: 0.24"

The wettest month (with the highest rainfall) is March (4.69").
The driest months (with the least rainfall) are July and August (0.04").

Average rainfall days in September
Volcano, CA

Average rainfall days in September - Volcano, CA
  • Average rainfall days in September: 3 days

The month with the highest number of rainy days is March (14.6 days).
The month with the least rainy days is August (1.5 days).

Average snowfall in September
Volcano, CA

Average snowfall in September - Volcano, CA
  • Average snowfall in September: 0"

The month with the highest snowfall is February (2.01").
The months with the least snowfall are January, April, May, June, July, August, September and October (0").

Average snowfall days in September
Volcano, CA

Average snowfall days in September - Volcano, CA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (1.3 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).

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

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

The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).

  • Average sunshine in September: 11h and 2min

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).

Average sunshine days in September
Volcano, CA

Average sunshine days in September - Volcano, CA
  • Average sunshine days in September: 26.5 days

The month with the most sunshine days is August (28.8 days).
The month with the least sunshine days is March (15.1 days).

Average UV index in September
Volcano, CA

Average UV index in September - Volcano, 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
Volcano, CA

Average cloud cover in September - Volcano, CA
  • Average cloud cover in September: 8

The month with the most cloud cover is March (Cloud cover 37).
The month with the least cloud cover is July (Cloud cover 4).

Average visibility in September
Volcano, CA

Average visibility in September - Volcano, 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).

Volcano, California, USA

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