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 into September marks the average high-temperature at a still moderately hot 75°F (23.9°C), differing minimally from August's 80.1°F (26.7°C). Porterfield, during the month of September, experiences an average low-temperature of 56.5°F (13.6°C).Humidity
In Porterfield, the average relative humidity in September is 77%.Rainfall
In Porterfield, in September, during 11.7 rainfall days, 2.24" (57mm) of precipitation is typically accumulated. In Porterfield, during the entire year, the rain falls for 151.3 days and collects up to 30.16" (766mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
In Porterfield, the average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:24 am and sunset at 7:28 pm. On the last day of September, sunrise is at 6:53 am and sunset at 6:39 pm CDT.
Sunshine
The average sunshine in September in Porterfield is 9h.UV index
In Porterfield, Illinois, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: The UV index of 4 during September leads to these advisories:
Ensure safety - Imperative it is to shield skin and eyes from damage. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. Employ a hat with a wide brim for robust protection, cutting UV exposure by half.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in September?
What is the average humidity in September in Porterfield?
How many days does it rain in September?
When it does not snow?
Does it snow in September?
How many hours of daylight does Porterfield have in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
How high is the UV index in September in Porterfield?
Average temperature in September
Porterfield, IL
- Average high temperature in September: 75°F
The warmest month (with the highest average high temperature) is July (81°F).
The month with the lowest average high temperature is January (29.3°F).
- Average low temperature in September: 56.5°F
The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (17.4°F).
Average pressure in September
Porterfield, 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
Porterfield, IL
- Average wind speed in September: 7.6mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in September
Porterfield, IL
- Average humidity in September: 77%
The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Porterfield, IL
- Average rainfall in September: 2.24"
The wettest month (with the highest rainfall) is May (4.41").
The driest months (with the least rainfall) are January and December (1.57").
Average rainfall days in September
Porterfield, IL
- Average rainfall days in September: 11.7 days
The month with the highest number of rainy days is May (18.4 days).
The month with the least rainy days is February (5.9 days).
Average snowfall in September
Porterfield, IL
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.7").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Porterfield, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.2 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
Porterfield, 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 18min).
- Average sunshine in September: 9h and 0min
The month with the most sunshine is June (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in September
Porterfield, IL
- Average sunshine days in September: 16.3 days
The month with the most sunshine days is November (17.7 days).
The month with the least sunshine days is May (10.7 days).
Average UV index in September
Porterfield, IL
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Porterfield, IL
- Average cloud cover in September: 32
The month with the most cloud cover is January (Cloud cover 59).
The months with the least cloud cover are August and September (Cloud cover 32).
Average visibility in September
Porterfield, IL
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, July and August (5mi).
Porterfield, Illinois, USA
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