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
A modest decline in the average high-temperature is seen during September, decreasing from a moderately hot 78.6°F (25.9°C) in August to an agreeable 72.3°F (22.4°C). During September, Round Lake Heights's temperature falls to a steady low-temperature average of 57°F (13.9°C).Humidity
In Round Lake Heights, the average relative humidity in September is 77%.Rainfall
In Round Lake Heights, in September, during 11.9 rainfall days, 1.57" (40mm) of precipitation is typically accumulated. In Round Lake Heights, during the entire year, the rain falls for 142.3 days and collects up to 21.97" (558mm) of precipitation.Snowfall
In Round Lake Heights, snow does not fall in June through September.Daylight
The average length of the day in September in Round Lake Heights is 12h and 28min.On the first day of September, sunrise is at 6:18 am and sunset at 7:25 pm. On the last day of the month, sunrise is at 6:49 am and sunset at 6:35 pm CDT.
Sunshine
The average sunshine in September is 8.9h.UV index
The average daily maximum UV index in September in Round Lake Heights is 4. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for average individuals.Note: The maximum daily UV index of 4 during September translates into the following directions:
Be vigilant - Suggestions to stave off sun damage are provided. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. Opt for tightly woven and loose clothing to enhance protection from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Round Lake Heights in September?
What is the average humidity in September in Round Lake Heights?
How much does it rain in Round Lake Heights in September?
When it does not snow in Round Lake Heights?
Does it snow in Round Lake Heights in September?
What is the average length of the day in September in Round Lake Heights?
What time are sunrise and sunset in September in Round Lake Heights?
How many hours of sunshine does Round Lake Heights have in September?
What is the UV index intensity in September in Round Lake Heights?
Average temperature in September
Round Lake Heights, IL
- Average high temperature in September: 72.3°F
The warmest month (with the highest average high temperature) is July (79.9°F).
The month with the lowest average high temperature is January (27.5°F).
- Average low temperature in September: 57°F
The month with the highest average low temperature is July (64.4°F).
The coldest month (with the lowest average low temperature) is January (16.5°F).
Average pressure in September
Round Lake Heights, IL
- Average pressure in September: 30.03"Hg
The months with the highest atmospheric pressure are January and February (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Round Lake Heights, IL
- Average wind speed in September: 7.5mph
The windiest month (with the highest average wind speed) is January (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).
Average humidity in September
Round Lake Heights, IL
- Average humidity in September: 77%
The months with the highest relative humidity are January and February (83%).
The month with the lowest relative humidity is October (74%).
Average rainfall in September
Round Lake Heights, IL
- Average rainfall in September: 1.57"
The wettest month (with the highest rainfall) is April (2.72").
The driest month (with the least rainfall) is December (0.98").
Average rainfall days in September
Round Lake Heights, IL
- Average rainfall days in September: 11.9 days
The month with the highest number of rainy days is July (17.5 days).
The month with the least rainy days is February (5 days).
Average snowfall in September
Round Lake Heights, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.58").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Round Lake Heights, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (13.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Round Lake Heights, 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 6min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is August (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in September
Round Lake Heights, IL
- Average sunshine days in September: 15.1 days
The month with the most sunshine days is November (17.1 days).
The month with the least sunshine days is May (10.8 days).
Average UV index in September
Round Lake Heights, IL
- Average UV index in September: 4
The months with the highest UV index are July and August (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Round Lake Heights, IL
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 61).
The months with the least cloud cover are July, August and September (Cloud cover 30).
Average visibility in September
Round Lake Heights, IL
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
Round Lake Heights, Illinois, USA
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