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 introduction of September sees an average high-temperature of a still moderately hot 80.8°F (27.1°C), hardly deviating from August. Boonville reports a substantial plunge from daytime highs during the nights of September, with an average low-temperature of 51.4°F (10.8°C).Heat index
Throughout September, the heat index is appraised at 82.4°F (28°C). With prolonged exposure and constant activity, one might feel exhausted and experience heat cramps.Research indicates the heat index considers values in shaded locales and with light winds. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'feels like', takes into account both air temperature and humidity to illustrate what people actually feel. Elements such as metabolic variations, being pregnant, and physical activity can impact one's weather perception. Taking into account that direct sunlight can boost the heat effect, the heat index may rise by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to babies and toddlers. Young children typically face greater hazards than adults because they do not sweat as much. Their larger skin surface in comparison to their little bodies and the high heat production from their active nature compounds their vulnerability.
Humidity
July and September, with an average relative humidity of 58%, are the least humid months.Rainfall
In September, the rain falls for 2.5 days. Throughout September, 0.2" (5mm) of precipitation is accumulated. Throughout the year, there are 83.3 rainfall days, and 17.72" (450mm) of precipitation is accumulated.Snowfall
January, March through December are months without snowfall.Daylight
In September, the average length of the day in Boonville is 12h and 25min.On the first day of the month, sunrise is at 6:43 am and sunset at 7:43 pm. On the last day of September, sunrise is at 7:09 am and sunset at 6:57 pm PDT.
Sunshine
In September, the average sunshine is 10.9h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for the average person.Note: The maximum daily UV index of 4 in September converts into the following recommendations:
Act with care - The suggestion to avoid sunburn is emphasized. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the least humid month?
What is the average humidity in September?
How much does it rain in September?
When it does not snow in Boonville?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index intensity in September in Boonville?
Average temperature in September
Boonville, CA
- Average high temperature in September: 80.8°F
The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is December (53.6°F).
- Average low temperature in September: 51.4°F
The month with the highest average low temperature is July (53.6°F).
The coldest month (with the lowest average low temperature) is December (37.4°F).
Average pressure in September
Boonville, 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
Boonville, CA
- Average wind speed in September: 4.4mph
The windiest months (with the highest average wind speed) are April, May and June (5.5mph).
The calmest month (with the lowest average wind speed) is November (4.2mph).
Average humidity in September
Boonville, CA
- Average humidity in September: 58%
The month with the highest relative humidity is March (79%).
The months with the lowest relative humidity are July and September (58%).
Average rainfall in September
Boonville, CA
- Average rainfall in September: 0.2"
The wettest months (with the highest rainfall) are February and December (3.11").
The driest months (with the least rainfall) are July and August (0.08").
Average rainfall days in September
Boonville, CA
- Average rainfall days in September: 2.5 days
The month with the highest number of rainy days is March (14.3 days).
The month with the least rainy days is August (1.3 days).
Average snowfall in September
Boonville, 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
Boonville, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.3 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
Boonville, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 10h and 5min
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 18min).
Average sunshine days in September
Boonville, CA
- Average sunshine days in September: 26.9 days
The month with the most sunshine days is July (28.5 days).
The month with the least sunshine days is March (15.9 days).
Average UV index in September
Boonville, CA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are February and November (UV index 2).
Average cloud cover in September
Boonville, CA
- Average cloud cover in September: 11
The month with the most cloud cover is March (Cloud cover 45).
The month with the least cloud cover is August (Cloud cover 6).
Average visibility in September
Boonville, CA
- Average visibility in September: 6mi
The months with the highest visibility are February, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, March and December (5mi).
Boonville, California, USA
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