September weather forecastKnightsen, CA
September
Weather in September
September, the first month of the autumn in Knightsen, is still a warm month, with an average temperature ranging between max 85.3°F (29.6°C) and min 57.7°F (14.3°C).Temperature
Knightsen's weather in September displays an average high-temperature of a warm 85.3°F (29.6°C), showing minor disparity from August's 87.4°F (30.8°C). September nights report a substantial dip from daytime highs to an average of 57.7°F (14.3°C).Heat index
The heat index value during September is estimated at a tropical 87.8°F (31°C). Extended exposure and activity might lead to tiredness, potentially resulting in heat cramps.Keep in mind the heat index values are meant for areas in shade and with light wind. Heat index values may surge by up to 15 Fahrenheit (8 Celsius) degrees in the presence of direct sunlight.
Note: The heat index, also known as 'real feel' or 'apparent temperature', is a measure that combines air temperature and relative humidity into a single value that indicates how hot the weather feels. This effect is personal, shaped by the individual's physical activity and heat sensitivity, influenced by factors including wind, clothing, and metabolic variances. With direct sunlight, be aware that it might enhance the heat sensation, raising the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for children. Young kids are often more at risk than adults as they tend to perspire less. Besides, their skin surface is larger relative to their small bodies, and their increased heat output from their active lifestyle compounds their risk.
Humidity
September is the least humid month, with an average relative humidity of 52%.Rainfall
In Knightsen, in September, during 1.3 rainfall days, 0.08" (2mm) of precipitation is typically accumulated. In Knightsen, during the entire year, the rain falls for 62 days and collects up to 10.16" (258mm) of precipitation.Snowfall
January through November are months without snowfall.Daylight
In September, the average length of the day is 12h and 25min.On the first day of the month, sunrise is at 6:37 am and sunset at 7:35 pm. On the last day of September, sunrise is at 7:02 am and sunset at 6:50 pm PDT.
Sunshine
In Knightsen, the average sunshine in September is 11.2h.UV index
In Knightsen, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for average individuals.Note: An average UV index of 5 in September transforms into this advice:
Be vigilant - A duty to shield skin and eyes from injury exists. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Knightsen, CA
- Average high temperature in September: 85.3°F
The warmest month (with the highest average high temperature) is July (88.5°F).
The month with the lowest average high temperature is December (55°F).
- Average low temperature in September: 57.7°F
The month with the highest average low temperature is September (57.7°F).
The coldest month (with the lowest average low temperature) is January (41.5°F).
Average pressure in September
Knightsen, CA
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Knightsen, CA
- Average wind speed in September: 6.2mph
The windiest month (with the highest average wind speed) is June (7.8mph).
The calmest months (with the lowest average wind speed) are January and November (4.5mph).
Average humidity in September
Knightsen, CA
- Average humidity in September: 52%
The month with the highest relative humidity is January (74%).
The month with the lowest relative humidity is September (52%).
Average rainfall in September
Knightsen, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is February (2.09").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in September
Knightsen, CA
- Average rainfall days in September: 1.3 days
The month with the highest number of rainy days is March (12.3 days).
The month with the least rainy days is August (0.8 days).
Average snowfall days in September
Knightsen, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is December (0.1 days).
The months with the least snowfall days are January, February, March, April, May, June, July, August, September, October and November (0 days).
Average daylight in September /
Average sunshine in September
Knightsen, 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 36min).
- Average sunshine in September: 11h and 12min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).
Average sunshine days in September
Knightsen, CA
- Average sunshine days in September: 28.5 days
The month with the most sunshine days is August (29.8 days).
The month with the least sunshine days is March (17.7 days).
Average UV index in September
Knightsen, 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
Knightsen, CA
- Average cloud cover in September: 8
The months with the most cloud cover are March and December (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 5).
Average visibility in September
Knightsen, 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).





