September weather forecastManchester, CA
September
Weather in September
The first month of the autumn, September, is still a warm month in Manchester, California, with an average temperature varying between 80.8°F (27.1°C) and 51.4°F (10.8°C).Temperature
September's arrival brings an average high-temperature of a still warm 80.8°F (27.1°C), demonstrating subtle variation from the preceding month. Manchester registers a significant drop in temperature in September, with average nighttime lows of 51.4°F (10.8°C).Heat index
Throughout September, the heat index is computed to be 82.4°F (28°C). Prolonged activity during exposure might result in a state of fatigue and cause heat cramps.Heat index evaluations are typically in the context of light winds and shaded environments. Heat index values may rise by up to 15 Fahrenheit (8 Celsius) degrees when exposed to direct sunlight.
Note: The heat index, also known as 'felt air temperature' or 'feels like', is a fusion of air temperature and moisture levels to demonstrate the sensation of heat. The impact of weather is personal, differing among a variety of people based on differences in body mass, height, and the level of physical exertion. Keep in mind that direct sunshine exposure can amplify the weather's effects, possibly increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are largely significant for babies and toddlers. Youngsters typically face more danger than adults since they sweat less. Their larger skin surface compared to their small bodies and heightened heat production from their activities augment their vulnerability.
Humidity
July and September, with an average relative humidity of 58%, are the least humid months.Rainfall
In Manchester, in September, it is raining for 2.5 days, with typically 0.2" (5mm) of accumulated precipitation. In Manchester, during the entire year, the rain falls for 83.3 days and collects up to 17.72" (450mm) of precipitation.Snowfall
January, March through December are months without snowfall.Daylight
In September, the average length of the day in Manchester, California, is 12h and 25min.On the first day of the month, sunrise is at 6:44 am and sunset at 7:44 pm. On the last day of September, in Manchester, sunrise is at 7:10 am and sunset at 6:58 pm PDT.
Sunshine
In Manchester, the average sunshine in September is 10.9h.UV index
In Manchester, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for ordinary individuals.Note: An average maximum UV index of 4 in September leads to these recommendations:
Guard yourself - Precautionary measures against sun damage are advocated. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Manchester, 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
Manchester, 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
Manchester, 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
Manchester, 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
Manchester, 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
Manchester, 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
Manchester, 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
Manchester, 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
Manchester, CA
- Average daylight in September: 12h and 24min
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 54min
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
Manchester, 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
Manchester, 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
Manchester, 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
Manchester, 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).





