September weather forecastByron, CA
September
Weather in September
September, the first month of the autumn in Byron, 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
The onset of September brings with it an average high-temperature of a moderately hot 85.3°F (29.6°C), showing a negligible variation from the month before. Byron anticipates a considerable drop in temperature at night in September, with an average low of 57.7°F (14.3°C).Heat index
September's mean heat index is calculated to be a hot 87.8°F (31°C). Ongoing exposure and activity could lead to a state of exhaustion, with a chance of heat cramps.In terms of the heat index, values are set with light wind and shade conditions in mind. Heat index values might soar by up to 15 Fahrenheit (8 Celsius) degrees with exposure to direct sunshine.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', takes into account both air temperature and humidity to illustrate what people actually feel. An individual's perception of weather can be swayed by a variety of elements including metabolic differences, pregnancy status, and their level of physical exertion. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for babies and toddlers. Youngsters frequently overlook the need for breaks and fluid intake. Thirst is an advanced sign of dehydration - thereby highlighting the importance of keeping hydrated, particularly during long physical activities.
Humidity
The least humid month is September, with an average relative humidity of 52%.Rainfall
In Byron, in September, during 1.3 rainfall days, 0.08" (2mm) of precipitation is typically accumulated. In Byron, California, 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 Byron, the average length of the day in September 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 September, the average sunshine is 11.2h.UV index
In September, the average daily maximum UV index is 5. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for average individuals.Note: In September, the UV index of 5 transforms into the following advice:
Exercise prevention - Protecting skin and eyes from harm is required. Direct Sun exposure should be minimized especially during midday when radiation is most intense. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Byron, 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
Byron, 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
Byron, 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
Byron, 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
Byron, 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
Byron, 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
Byron, 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
Byron, CA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 42min).
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
Byron, 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
Byron, 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
Byron, 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
Byron, 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).





