Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
September's arrival subtly correlates with a reduction in the average high-temperature, down from a hot 86.5°F (30.3°C) in August to a moderately hot 81.1°F (27.3°C). In September, in Simpson, the average low-temperature is a mild 60.6°F (15.9°C).Heat index
The heat index value during September is evaluated at a tropical 86°F (30°C). If activity and exposure persist, they could induce fatigue, leading to possible heat cramps.In terms of the heat index, values are set with light wind and shade conditions in mind. A rise in the heat index by 15 Fahrenheit (8 Celsius) degrees may result from direct sunlight exposure.
Note: The heat index, also known as 'felt air temperature' or 'feels like', arises from combining readings of air temperature and relative moisture content. A person's impression of weather can be shaped by several aspects, among them metabolic variations, pregnancy, and levels of physical activity. It is essential to be conscious of the fact that direct sunlight can intensify the felt heat, leading to an elevation in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular importance for children. Young individuals usually face greater risks than adults as their sweat production is less. Also, their larger skin surface relative to their small bodies and the high heat generation due to their activity contributes to their vulnerability.
Humidity
In September, the average relative humidity in Simpson, Illinois, is 73%.Rainfall
The month with the least rainfall in Simpson is September, when the rain falls for 8.3 days and typically collects 0.47" (12mm) of precipitation.Snowfall
In Simpson, Illinois, snow does not fall in April through October.Daylight
In September, the average length of the day in Simpson is 12h and 25min.On the first day of September, sunrise is at 6:26 am and sunset at 7:23 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 6:39 pm CDT.
Sunshine
The average sunshine in September in Simpson is 9.4h.UV index
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 unsafe exposure to UV radiation for the ordinary person.Note: In September, a daily UV index of 5 turns into the following recommendations:
Put precautions into practice - Protective measures against sun-induced damage are advised. The solar radiation around mid-day is intense; avoid the Sun and stay safe. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in Simpson in September?
What is the average humidity in September in Simpson?
What is the driest month in Simpson?
How many days does it rain in September in Simpson?
When it does not snow in Simpson?
How many hours of daylight does Simpson have in September?
What time are sunrise and sunset in September in Simpson?
How long on average sun shines in September in Simpson?
How high is the UV index in September in Simpson?
Average temperature in September
Simpson, IL
- Average high temperature in September: 81.1°F
The warmest month (with the highest average high temperature) is July (88°F).
The month with the lowest average high temperature is January (40.1°F).
- Average low temperature in September: 60.6°F
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (27°F).
Average pressure in September
Simpson, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Simpson, IL
- Average wind speed in September: 6.3mph
The windiest months (with the highest average wind speed) are January and February (9mph).
The calmest months (with the lowest average wind speed) are July and August (5.7mph).
Average humidity in September
Simpson, IL
- Average humidity in September: 73%
The months with the highest relative humidity are March and May (79%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Simpson, IL
- Average rainfall in September: 0.47"
The wettest month (with the highest rainfall) is June (1.5").
The driest month (with the least rainfall) is September (0.47").
Average rainfall days in September
Simpson, IL
- Average rainfall days in September: 8.3 days
The month with the highest number of rainy days is July (13.1 days).
The months with the least rainy days are January, February and December (7.3 days).
Average snowfall in September
Simpson, IL
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.67").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Simpson, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (3.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Simpson, IL
- Average daylight in September: 12h and 2min
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: 9h and 2min
The months with the most sunshine are June and July (Average sunshine: 10h and 24min).
The months with the least sunshine are January and February (Average sunshine: 4h and 36min).
Average sunshine days in September
Simpson, IL
- Average sunshine days in September: 19.1 days
The month with the most sunshine days is October (21.5 days).
The month with the least sunshine days is June (14.8 days).
Average UV index in September
Simpson, IL
- Average UV index in September: 5
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February and December (UV index 2).
Average cloud cover in September
Simpson, IL
- Average cloud cover in September: 28
The months with the most cloud cover are January and February (Cloud cover 51).
The month with the least cloud cover is September (Cloud cover 28).
Average visibility in September
Simpson, IL
- 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).
Simpson, Illinois, USA
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