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 onset of September is marked by a minor decrease in temperature, transitioning from 83.8°F (28.8°C) in August to a still moderately hot 78.4°F (25.8°C). In Walnut Hill, September nights cool down to an average of 59.9°F (15.5°C).Humidity
In September, the average relative humidity in Walnut Hill, Illinois, is 75%.Rainfall
September is the month with the least rainfall in Walnut Hill, Illinois. Rain falls for 6.3 days and accumulates 0.24" (6mm) of precipitation.Snowfall
April through October are months without snowfall in Walnut Hill.Daylight
In Walnut Hill, Illinois, the average length of the day in September is 12h and 25min.On the first day of the month, sunrise is at 6:26 am and sunset at 7:25 pm. On the last day of September, sunrise is at 6:51 am and sunset at 6:40 pm CDT.
Sunshine
In Walnut Hill, the average sunshine in September is 9.1h.UV index
In September, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for the ordinary person.Note: In September, an average UV index of 5 transforms into the following instructions:
Prioritize safety - Suggestions to prevent sun damage are offered. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Walnut Hill in September?
What is the average humidity in September in Walnut Hill?
What is the driest month in Walnut Hill?
How much does it rain in Walnut Hill in September?
When it does not snow in Walnut Hill?
What is the average length of the day in September in Walnut Hill?
When is the sunrise / sunset in September in Walnut Hill?
How long on average sun shines in September in Walnut Hill?
What is the UV index intensity in September in Walnut Hill?
Average temperature in September
Walnut Hill, IL
- Average high temperature in September: 78.4°F
The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is January (37.2°F).
- Average low temperature in September: 59.9°F
The month with the highest average low temperature is July (67.6°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in September
Walnut Hill, 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 (29.93"Hg).
Average wind speed in September
Walnut Hill, IL
- Average wind speed in September: 6.5mph
The windiest month (with the highest average wind speed) is February (10mph).
The calmest month (with the lowest average wind speed) is July (5.8mph).
Average humidity in September
Walnut Hill, IL
- Average humidity in September: 75%
The months with the highest relative humidity are May and July (80%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Walnut Hill, IL
- Average rainfall in September: 0.24"
The wettest months (with the highest rainfall) are April and July (0.75").
The driest month (with the least rainfall) is September (0.24").
Average rainfall days in September
Walnut Hill, IL
- Average rainfall days in September: 6.3 days
The month with the highest number of rainy days is May (10.1 days).
The month with the least rainy days is January (3.7 days).
Average snowfall in September
Walnut Hill, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.28").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Walnut Hill, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (3.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Walnut Hill, IL
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 9h and 1min
The months with the most sunshine are June and July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in September
Walnut Hill, IL
- Average sunshine days in September: 21.4 days
The months with the most sunshine days are January and December (24.5 days).
The month with the least sunshine days is May (16.8 days).
Average UV index in September
Walnut Hill, 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, November and December (UV index 2).
Average cloud cover in September
Walnut Hill, IL
- Average cloud cover in September: 30
The months with the most cloud cover are January and February (Cloud cover 51).
The month with the least cloud cover is June (Cloud cover 28).
Average visibility in September
Walnut Hill, 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).
Walnut Hill, Illinois, USA
Weather forecast for your location
2. Allow the app to use your location