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
Marengo in September undergoes a slight reduction in the average high-temperature, shifting from August's warm 78.1°F (25.6°C) to an agreeable 72.1°F (22.3°C). During the nights in September, an average low-temperature of 54.1°F (12.3°C) is observed.Humidity
The average relative humidity in September is 81%.Rainfall
In Marengo, during September, the rain falls for 12.8 days and regularly aggregates up to 2.09" (53mm) of precipitation. Throughout the year, in Marengo, there are 154.6 rainfall days, and 30.31" (770mm) of precipitation is accumulated.Snowfall
In Marengo, snow does not fall in May through September.Daylight
In September, the average length of the day is 12h and 28min.On the first day of the month, sunrise is at 6:20 am and sunset at 7:27 pm. On the last day of September, sunrise is at 6:51 am and sunset at 6:37 pm CDT.
Sunshine
The average sunshine in September is 8.5h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for the ordinary person.Note: In September, the maximum UV index of 4 translates into these guidelines:
Be vigilant - Suggestions to stave off sun damage are provided. Considering the Sun's intensity during midday, it's wise to minimize direct exposure. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
Does it snow in September?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Marengo, IL
- Average high temperature in September: 72.1°F
The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is January (26.1°F).
- Average low temperature in September: 54.1°F
The month with the highest average low temperature is July (62.6°F).
The coldest month (with the lowest average low temperature) is January (13.8°F).
Average pressure in September
Marengo, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Marengo, IL
- Average wind speed in September: 7.1mph
The windiest month (with the highest average wind speed) is April (9.9mph).
The calmest month (with the lowest average wind speed) is August (6.1mph).
Average humidity in September
Marengo, IL
- Average humidity in September: 81%
The month with the highest relative humidity is January (86%).
The month with the lowest relative humidity is October (76%).
Average rainfall in September
Marengo, IL
- Average rainfall in September: 2.09"
The wettest month (with the highest rainfall) is June (4.21").
The driest months (with the least rainfall) are February and November (1.5").
Average rainfall days in September
Marengo, IL
- Average rainfall days in September: 12.8 days
The month with the highest number of rainy days is July (19.3 days).
The month with the least rainy days is February (4.8 days).
Average snowfall in September
Marengo, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (5.28").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Marengo, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (12.3 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
Marengo, IL
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 8h and 3min
The month with the most sunshine is July (Average sunshine: 9h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in September
Marengo, IL
- Average sunshine days in September: 14.8 days
The month with the most sunshine days is November (17.5 days).
The month with the least sunshine days is June (9.5 days).
Average UV index in September
Marengo, IL
- Average UV index in September: 4
The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Marengo, IL
- Average cloud cover in September: 35
The month with the most cloud cover is January (Cloud cover 63).
The months with the least cloud cover are August and September (Cloud cover 35).
Average visibility in September
Marengo, IL
- Average visibility in September: 5mi
The months with the highest visibility are March, April, May, June, October, November and December (6mi).
The months with the lowest visibility are January, February, July, August and September (5mi).
Marengo, Illinois, USA
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