September weather forecastWinters, CA
September
Weather in September
The first month of the autumn, September, is also a hot month in Winters, California, with temperature in the range of an average low of 58.1°F (14.5°C) and an average high of 88.3°F (31.3°C).Temperature
The shift from August to September is characterized by an average high-temperature of a still tropical 88.3°F (31.3°C), not significantly different from the 92.7°F (33.7°C) of August. September nights are characterized by a notable drop from daytime highs, with an average low-temperature of 58.1°F (14.5°C).Heat index
September's mean heat index is calculated to be a tropical 89.6°F (32°C). With ongoing exposure and activity, one might experience weariness, and heat cramps could ensue.Heat index details are generally centered around shaded locations and a mild breeze. Direct sunlight can potentially boost the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', binds temperature metrics with humidity values to give a sense of the actual warmth. A person's impression of weather can be swayed by numerous aspects, among them metabolic variations, pregnancy, and activity levels. One should be aware that direct sunshine can amplify the perceived temperature, raising the heat index by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly important for children. Young individuals are typically more threatened than adults due to their reduced perspiration. Also, the larger skin surface proportionate to their small bodies and the increased heat from their activities magnify their risk.
Humidity
The least humid month in Winters is September, with an average relative humidity of 46%.Rainfall
In Winters, in September, it is raining for 1.5 days, with typically 0.08" (2mm) of accumulated precipitation. Throughout the year, there are 71.7 rainfall days, and 13.43" (341mm) of precipitation is accumulated.Snowfall
February through December are months without snowfall.Daylight
In September, the average length of the day is 12h and 25min.On the first day of September, sunrise is at 6:37 am and sunset at 7:37 pm. On the last day of the month, sunrise is at 7:03 am and sunset at 6:51 pm PDT.
Sunshine
The average sunshine in September is 11.1h.UV index
The average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for ordinary individuals.Note: The UV index of 5 in September translates into these instructions:
Exercise prevention - Warding off sunburn is urged. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Winters, CA
- Average high temperature in September: 88.3°F
The warmest month (with the highest average high temperature) is July (93°F).
The month with the lowest average high temperature is December (54.3°F).
- Average low temperature in September: 58.1°F
The month with the highest average low temperature is August (58.3°F).
The coldest month (with the lowest average low temperature) is January (40.8°F).
Average pressure in September
Winters, CA
- Average pressure in September: 29.91"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.91"Hg).
Average wind speed in September
Winters, CA
- Average wind speed in September: 5.4mph
The windiest month (with the highest average wind speed) is May (6.6mph).
The calmest months (with the lowest average wind speed) are January and November (5mph).
Average humidity in September
Winters, CA
- Average humidity in September: 46%
The month with the highest relative humidity is March (76%).
The month with the lowest relative humidity is September (46%).
Average rainfall in September
Winters, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is February (2.68").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in September
Winters, CA
- Average rainfall days in September: 1.5 days
The month with the highest number of rainy days is March (12.7 days).
The month with the least rainy days is July (0.8 days).
Average snowfall in September
Winters, CA
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.1").
The months with the least snowfall are February, March, April, May, June, July, August, September, October, November and December (0").
Average snowfall days in September
Winters, 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
Winters, 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 6min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).
Average sunshine days in September
Winters, CA
- Average sunshine days in September: 28.3 days
The month with the most sunshine days is July (30.1 days).
The month with the least sunshine days is March (16.9 days).
Average UV index in September
Winters, CA
- Average UV index in September: 5
The months with the highest UV index are June and July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in September
Winters, CA
- Average cloud cover in September: 9
The months with the most cloud cover are March and December (Cloud cover 39).
The month with the least cloud cover is July (Cloud cover 5).
Average visibility in September
Winters, 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).





