September weather forecast and climate
Healdsburg, CA

Neat rows of plants in a farm with a view of a red farmhouse up the hill in Healdsburg, California
Neat rows of plants in a farm with a view of a red farmhouse up the hill in Healdsburg, California

Weather in September

The first month of the autumn, September, is also a moderately hot month in Healdsburg, California, with temperature in the range of an average high of 82.6°F (28.1°C) and an average low of 53.6°F (12°C).

Temperature

In Healdsburg, the average high-temperature is almost the same as in August - a still warm 82.6°F (28.1°C). In September, in Healdsburg, the average low-temperature is 53.6°F (12°C).

Heat index

The average heat index in September is appraised at 84.7°F (29.3°C). Constant exposure and activity lead to possible fatigue. Prolonged exercise may result in heat cramps.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like', 'felt air temperature', 'real feel', or 'apparent temperature', is what the temperature feels like to the human body when the air temperature is combined with the relative humidity. Additional factors like activity, wind, pregnancy, and metabolic differences affect individual temperature impact. Be aware that direct exposure to sunlight increases heat impact, and may raise the heat index additionally, by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.

Humidity

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

Rainfall

In Healdsburg, California, during September, the rain falls for 2.2 days and regularly aggregates up to 0.12" (3mm) of precipitation. In Healdsburg, during the entire year, the rain falls for 81.2 days and collects up to 19.84" (504mm) of precipitation.

Snowfall

January, March through December are months without snowfall in Healdsburg.

Daylight

In Healdsburg, the average length of the day is 12.4h.

Sunshine

The average sunshine in Healdsburg is 11h.

UV index

In September, the average daily maximum UV index in Healdsburg, California, is 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to the UV radiation for the average person.
Note: The average daily UV index of 5 transform into the following instructions:
Take precautions - Protection against sun damage is advised. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
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FAQ

What is the temperature in September in Healdsburg?

The average high-temperature, in September, in Healdsburg, California, is 82.6°F (28.1°C), while the average low-temperature is 53.6°F (12°C). In September, the average heat index (a.k.a. 'real feel', 'apparent temperature'), that combines relative humidity and air temperature, is appraised at 84.7°F (29.3°C).

What is the least humid month in Healdsburg?

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

What is the average humidity in September in Healdsburg?

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

How much does it rain in Healdsburg in September?

In September, the rain falls for 2.2 days. Throughout September, 0.12" (3mm) of precipitation is accumulated.

When it does not snow in Healdsburg?

In Healdsburg snow does not fall in January, March through December.

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

In September, the average length of the day in Healdsburg is 12.4h.

How many hours of sunshine does Healdsburg have in September?

The average sunshine in September in Healdsburg is 11h.

How high is the UV index in September in Healdsburg?

The average daily maximum UV index in September in Healdsburg is 5. A UV Index estimate of 3 to 5 represents a medium health risk from the exposure to the Sun's UV radiation.

Average temperature in September
Healdsburg, CA

Average temperature in September - Healdsburg, CA
  • Average high temperature in September: 82.6°F

The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is December (55°F).

  • Average low temperature in September: 53.6°F

The month with the highest average low temperature is August (55°F).
The coldest month (with the lowest average low temperature) is December (40.1°F).

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Average pressure in September
Healdsburg, CA

Average pressure in September - Healdsburg, CA
  • Average pressure in September: 29.92"

The month with the highest atmospheric pressure is January (30.13").
Months with the lowest atmospheric pressure are June, August and September (29.92").

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Average wind speed in September
Healdsburg, CA

Average wind speed in September - Healdsburg, CA
  • Average wind speed in September: 4.7mph

The windiest months (with the highest average wind speed) are April and May (6.2mph).
The calmest month (with the lowest average wind speed) is November (4.5mph).

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Average humidity in September
Healdsburg, CA

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

The month with the highest relative humidity is March (76%).
The month with the lowest relative humidity is September (57%).

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Average rainfall in September
Healdsburg, CA

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

The wettest month (with the highest rainfall) is February (4.33").
The driest months (with the least rainfall) are July and August (0.04").

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Average rainfall days in September
Healdsburg, CA

Average rainfall days in September - Healdsburg, CA
  • Average rainfall days in September: 2.2 days

The month with the highest number of rainy days is March (14.2 days).
The month with the least rainy days is August (0.8 days).

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Average snowfall in September
Healdsburg, CA

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

The month with the highest snowfall is February (0.04").
Months with the least snowfall are January, March, April, May, June, July, August, September, October, November and December (0").

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Average snowfall days in September
Healdsburg, CA

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

The month with the highest number of snowfall days is February (0.1 days).
Months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).

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

Average daylight in September / Average sunshine in September - Healdsburg, CA
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.8h).
The month with the shortest days is December (Average daylight: 9.5h).

  • Average sunshine in September: 11h

The month with the most sunshine is July (Average sunshine: 12h).
The month with the least sunshine is December (Average sunshine: 5.6h).

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Average sunshine days in September
Healdsburg, CA

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

The month with the most sunshine days is July (29.8 days).
The month with the least sunshine days is March (14.8 days).

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Average UV index in September
Healdsburg, CA

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

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

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Average cloud cover in September
Healdsburg, CA

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

The month with the most cloud cover is March (Cloud cover 41).
Months with the least cloud cover are July and August (Cloud cover 6).

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Average visibility in September
Healdsburg, CA

Average visibility in September - Healdsburg, CA
  • Average visibility in September: 6mi

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

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