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 is characterized by a mild reduction in the average high-temperature, from 79.9°F (26.6°C) in August to a still warm 73.6°F (23.1°C). In September, Merrionette Park experiences a temperature dip to an average of 59.2°F (15.1°C) at night.Humidity
In Merrionette Park, the average relative humidity in September is 75%.Rainfall
In Merrionette Park, during September, the rain falls for 13.5 days and regularly aggregates up to 1.97" (50mm) of precipitation. Throughout the year, there are 147.7 rainfall days, and 23.62" (600mm) of precipitation is accumulated.Snowfall
In Merrionette Park, snow does not fall in May through September.Daylight
In Merrionette Park, the average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:17 am and sunset at 7:23 pm. On the last day of September, sunrise is at 6:47 am and sunset at 6:33 pm CDT.
Sunshine
In September, the average sunshine is 9.1h.UV index
In Merrionette Park, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV radiation for the ordinary person.Note: The maximum UV index, 4 during September, leads to the following recommendations:
Ensure safety - Recommendations to avert sunburn are presented. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in Merrionette Park in September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
Does it snow in September?
How many hours of daylight does Merrionette Park have in September?
When are sunrise and sunset in September?
How many hours of sunshine does Merrionette Park have in September?
What is the UV index reading in September?
Average temperature in September
Merrionette Park, IL
- Average high temperature in September: 73.6°F
The warmest month (with the highest average high temperature) is July (81°F).
The month with the lowest average high temperature is January (29.5°F).
- Average low temperature in September: 59.2°F
The month with the highest average low temperature is July (66.6°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure in September
Merrionette Park, 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
Merrionette Park, IL
- Average wind speed in September: 7.7mph
The windiest month (with the highest average wind speed) is January (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in September
Merrionette Park, IL
- Average humidity in September: 75%
The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Merrionette Park, IL
- Average rainfall in September: 1.97"
The wettest month (with the highest rainfall) is May (3.07").
The driest month (with the least rainfall) is December (1.02").
Average rainfall days in September
Merrionette Park, IL
- Average rainfall days in September: 13.5 days
The month with the highest number of rainy days is July (18 days).
The month with the least rainy days is February (4.9 days).
Average snowfall in September
Merrionette Park, IL
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.07").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Merrionette Park, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.8 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
Merrionette Park, 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: 9h and 1min
The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in September
Merrionette Park, IL
- Average sunshine days in September: 13 days
The month with the most sunshine days is November (17.5 days).
The month with the least sunshine days is July (9.8 days).
Average UV index in September
Merrionette Park, IL
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Merrionette Park, IL
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 28).
Average visibility in September
Merrionette Park, 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).
Merrionette Park, Illinois, USA
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