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
The transition from August to September sees average high-temperatures adjusting to a still warm 74.3°F (23.5°C), from a not significantly different 79.5°F (26.4°C). September nights in Walnut cool down to an average low-temperature of 55.8°F (13.2°C).Humidity
In September, the average relative humidity is 78%.Rainfall
In Walnut, in September, during 9.1 rainfall days, 0.94" (24mm) of precipitation is typically accumulated. In Walnut, during the entire year, the rain falls for 114.5 days and collects up to 12.72" (323mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
In Walnut, the average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:25 am and sunset at 7:31 pm. On the last day of September, sunrise is at 6:54 am and sunset at 6:41 pm CDT.
Sunshine
The average sunshine in September is 8.9h.UV index
In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for average individuals.Note: The maximum UV index of 4 during September translates into these guidelines:
Be mindful. Individuals with a lighter skin tone may suffer burns in less than 30 minutes. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Walnut in September?
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?
When is the sunrise / sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Walnut, IL
- Average high temperature in September: 74.3°F
The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (27.5°F).
- Average low temperature in September: 55.8°F
The month with the highest average low temperature is July (64.2°F).
The coldest month (with the lowest average low temperature) is January (15.6°F).
Average pressure in September
Walnut, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Walnut, IL
- Average wind speed in September: 7.6mph
The windiest month (with the highest average wind speed) is April (10.5mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in September
Walnut, IL
- Average humidity in September: 78%
The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (73%).
Average rainfall in September
Walnut, IL
- Average rainfall in September: 0.94"
The wettest month (with the highest rainfall) is May (2.01").
The driest month (with the least rainfall) is January (0.55").
Average rainfall days in September
Walnut, IL
- Average rainfall days in September: 9.1 days
The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is January (3.8 days).
Average snowfall in September
Walnut, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.57").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Walnut, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10.1 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
Walnut, IL
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 8h and 5min
The months with the most sunshine are June, July and August (Average sunshine: 9h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in September
Walnut, IL
- Average sunshine days in September: 19.4 days
The month with the most sunshine days is December (20.8 days).
The month with the least sunshine days is June (13.5 days).
Average UV index in September
Walnut, IL
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Walnut, IL
- Average cloud cover in September: 32
The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is September (Cloud cover 32).
Average visibility in September
Walnut, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
Walnut, Illinois, USA
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