Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The ushering in of September brings an average high-temperature of a still moderately hot 82.6°F (28.1°C), closely mirroring the 84.6°F (29.2°C) of August. In September, the temperature registers a significant dip to an average of 53.6°F (12°C) at night.Heat index
Throughout September, the heat index is evaluated at 84.2°F (29°C). Prolonged exposure combined with continuous activity could lead to exhaustion, and possibly heat cramps.Given the heat index, its values are aligned with shaded sites and gentle winds. Exposure to the sun directly might heighten the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'real feel', determines the feeling of heat when you account for the relative humidity. Elements such as metabolic variations, being pregnant, and physical activity can impact one's weather perception. Direct exposure to sun rays can potentially augment the heat sensation, elevating the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical to babies and toddlers. Youngsters typically face more danger than adults since they sweat less. Their larger skin surface compared to their small bodies and heightened heat production from their activities augment their vulnerability.
Humidity
The least humid month is September, with an average relative humidity of 57%.Rainfall
In Healdsburg, 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.Daylight
The average length of the day in September in Healdsburg is 12h and 25min.On the first day of September, sunrise is at 6:41 am and sunset at 7:40 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 6:55 pm PDT.
Sunshine
The average sunshine in September in Healdsburg is 11h.UV index
The average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for ordinary individuals.Note: In September, the maximum UV index of 5 transforms into these recommendations:
Take precautions - Protection against sun damage is advised. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it hot in Healdsburg during September?
What is the least humid month in Healdsburg?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
How many hours of daylight does Healdsburg have in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
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).
Average pressure in September
Healdsburg, CA
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).
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).
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%).
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").
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).
Average snowfall in September
Healdsburg, CA
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.04").
The months with the least snowfall are January, March, April, May, June, July, August, September, October, November and December (0").
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).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in September /
Average sunshine in September
Healdsburg, 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 0min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 36min).
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).
Average UV index in September
Healdsburg, 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
Healdsburg, CA
- Average cloud cover in September: 9
The month with the most cloud cover is March (Cloud cover 41).
The months with the least cloud cover are July and August (Cloud cover 6).
Average visibility in September
Healdsburg, 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).
Healdsburg, California, USA
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