September weather forecast
South Holland, IL

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Weather in September

The first month of the autumn, September, is still a warm month in South Holland, Illinois, with an average temperature varying between 73.8°F (23.2°C) and 59.2°F (15.1°C).

Temperature

September signifies a gentle decline in South Holland's average high-temperature, easing from 79.3°F (26.3°C) in August to a still warm 73.8°F (23.2°C). South Holland registers a consistent average low-temperature of 59.2°F (15.1°C) during September.

Humidity

The average relative humidity in September is 75%.

Rainfall

In South Holland, in September, it is raining for 9.8 days, with typically 0.91" (23mm) of accumulated precipitation. In South Holland, during the entire year, the rain falls for 110.3 days and collects up to 10.31" (262mm) of precipitation.

Snowfall

In South Holland, snow does not fall in May through September.

Daylight

In September, the average length of the day is 12h and 28min.
On the first day of September, sunrise is at 6:17 am and sunset at 7:23 pm. On the last day of the month, sunrise is at 6:46 am and sunset at 6:33 pm CDT.

Sunshine

The average sunshine in September is 8.9h.

UV index

In South Holland, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.
Note: In September, the maximum UV index of 4 suggests this advice:
Ensure safety - Imperative it is to shield skin and eyes from damage. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. Boost your sun resistance with garments that are densely woven yet spacious.

Frequently asked questions

What is the usual temperature for South Holland in September?

In September, in South Holland, the average high-temperature is 73.8°F (23.2°C), and the average low-temperature is 59.2°F (15.1°C).

What is the average humidity in September?

The average relative humidity in September is 75%.

How much does it rain in September?

In South Holland, in September, during 9.8 rainfall days, 0.91" (23mm) of precipitation is typically accumulated.

When it does not snow?

In South Holland, snow does not fall in May through September.

Does it snow in September?

In South Holland, in September, it doesn't snow. In October, it regularly snows.

What is the average length of the day in September in South Holland?

In September, the average day length is 12h and 28min.

When is the sunrise / sunset in September in South Holland?

In September, on the first day of the month, sunrise is at 6:17 am and sunset at 7:23 pm. On the last day of the month, sunrise is at 6:46 am and sunset at 6:33 pm CDT.

How many hours of sunshine does South Holland have in September?

The average sunshine duration in September is 8.9h.

What is the UV index intensity in September?

In South Holland, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium hazard to health from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
South Holland, IL

Average temperature in September - South Holland, IL
  • Average high temperature in September: 73.8°F

The warmest month (with the highest average high temperature) is July (80.1°F).
The month with the lowest average high temperature is January (29.8°F).

  • Average low temperature in September: 59.2°F

The month with the highest average low temperature is July (66.9°F).
The coldest month (with the lowest average low temperature) is January (19.6°F).

Average pressure in September
South Holland, IL

Average pressure in September - South Holland, 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
South Holland, IL

Average wind speed in September - South Holland, IL
  • Average wind speed in September: 8mph

The windiest month (with the highest average wind speed) is January (11mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).

Average humidity in September
South Holland, IL

Average humidity in September - South Holland, 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
South Holland, IL

Average rainfall in September - South Holland, IL
  • Average rainfall in September: 0.91"

The wettest months (with the highest rainfall) are May and June (1.38").
The driest months (with the least rainfall) are February and December (0.47").

Average rainfall days in September
South Holland, IL

Average rainfall days in September - South Holland, IL
  • Average rainfall days in September: 9.8 days

The month with the highest number of rainy days is July (14 days).
The month with the least rainy days is February (4.1 days).

Average snowfall in September
South Holland, IL

Average snowfall in September - South Holland, IL
  • Average snowfall in September: 0"

The month with the highest snowfall is January (1.1").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in September
South Holland, IL

Average snowfall days in September - South Holland, IL
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (9.3 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
South Holland, IL

Average daylight in September / Average sunshine in September - South Holland, 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 month with the most sunshine is August (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).

Average sunshine days in September
South Holland, IL

Average sunshine days in September - South Holland, IL
  • Average sunshine days in September: 16.9 days

The month with the most sunshine days is December (19.8 days).
The month with the least sunshine days is June (13.1 days).

Average UV index in September
South Holland, IL

Average UV index in September - South Holland, 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
South Holland, IL

Average cloud cover in September - South Holland, IL
  • Average cloud cover in September: 31

The month with the most cloud cover is January (Cloud cover 62).
The month with the least cloud cover is August (Cloud cover 28).

Average visibility in September
South Holland, IL

Average visibility in September - South Holland, 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).

South Holland, Illinois, USA

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