September weather forecastOakville, CA
September
Weather in September
The first month of the autumn, September, is still a warm month in Oakville, California, with an average temperature varying between 55.2°F (12.9°C) and 84°F (28.9°C).Temperature
During September, Oakville records an average high-temperature of a warm 84°F (28.9°C), marking a slight divergence from August's 86.2°F (30.1°C). Against the high September temperatures, Oakville records an average drop to a cool 55.2°F (12.9°C) at night.Heat index
The heat index value during September is calculated to be a hot 86°F (30°C). If activity and exposure persist, they could induce fatigue, leading to possible heat cramps.It is important to note that the heat index values are for shaded areas and light wind scenarios. Exposure to the direct sun could elevate the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', is a measure that combines air temperature and relative humidity into a single value that indicates how hot the weather feels. The experience of temperature can be subjective, varying based on the individual's activity and heat perception, influenced by factors like wind, attire, and metabolic variations. Under direct sun rays, the felt temperature might be heightened, with the heat index increasing by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold great significance to children. 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
The least humid month in Oakville is September, with an average relative humidity of 54%.Rainfall
In Oakville, California, in September, during 2.1 rainfall days, 0.08" (2mm) of precipitation is typically accumulated. Throughout the year, in Oakville, there are 77.8 rainfall days, and 16.02" (407mm) of precipitation is accumulated.Daylight
The average length of the day in September is 12h and 25min.On the first day of the month, sunrise is at 6:39 am and sunset at 7:38 pm. On the last day of September, in Oakville, sunrise is at 7:05 am and sunset at 6:53 pm PDT.
Sunshine
In September, the average sunshine is 11.1h.UV index
In Oakville, California, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV radiation for the average person.Note: In September, the average maximum UV index of 5 translates into the following recommendations:
Guard yourself - An obligation to protect skin and eyes from harm exists. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Oakville, CA
- Average high temperature in September: 84°F
The warmest month (with the highest average high temperature) is July (86.5°F).
The month with the lowest average high temperature is December (54.5°F).
- Average low temperature in September: 55.2°F
The month with the highest average low temperature is August (55.4°F).
The coldest month (with the lowest average low temperature) is December (40.1°F).
Average pressure in September
Oakville, 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 and August (29.91"Hg).
Average wind speed in September
Oakville, CA
- Average wind speed in September: 4.7mph
The windiest month (with the highest average wind speed) is May (6mph).
The calmest month (with the lowest average wind speed) is November (4.3mph).
Average humidity in September
Oakville, CA
- Average humidity in September: 54%
The month with the highest relative humidity is March (76%).
The month with the lowest relative humidity is September (54%).
Average rainfall in September
Oakville, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is February (3.43").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in September
Oakville, CA
- Average rainfall days in September: 2.1 days
The month with the highest number of rainy days is March (13.9 days).
The month with the least rainy days is August (0.9 days).
Average daylight in September /
Average sunshine in September
Oakville, CA
- Average daylight in September: 12h and 24min
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 6min
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
Oakville, CA
- Average sunshine days in September: 26.9 days
The month with the most sunshine days is July (29.4 days).
The month with the least sunshine days is March (15.8 days).
Average UV index in September
Oakville, 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
Oakville, CA
- Average cloud cover in September: 9
The month with the most cloud cover is March (Cloud cover 40).
The month with the least cloud cover is July (Cloud cover 6).
Average visibility in September
Oakville, 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).
