September weather forecast
Zion, IL

Today
Tomorrow
Long-term
YearJFMAMJJASeptemberOND
Contents

September

Weather in September

The first month of the autumn, September, is also an agreeable month in Zion, Illinois, with an average temperature ranging between max 21.6°C and min 14.7°C.

Temperature

September is characterized by a mild reduction in the average high-temperature, from a warm 25°C in August to an agreeable 21.6°C. During September, Zion records an average temperature of 14.7°C at night.

Humidity

In September, the average relative humidity is 77%.

Rainfall

In Zion, in September, during 12.7 rainfall days, 44mm of precipitation is typically accumulated. Throughout the year, there are 142.5 rainfall days, and 546mm of precipitation is accumulated.

Snowfall

In Zion, snow does not fall in May through September.

Daylight

In Zion, the average length of the day in September is 12h and 28min.
On the first day of September in Zion, sunrise is at 6:17 am and sunset at 7:24 pm. On the last day of the month, sunrise is at 6:48 am and sunset at 6:33 pm CDT.

Sunshine

The average sunshine in September in Zion is 9.2h.

UV index

In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for the average person.
Note: The UV index of 4 in September translates into these instructions:
Ensure safety - Recommendations to avert sunburn are presented. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. Sun protection is enhanced with clothing that boasts a tight weave yet offers a loose fit.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the average September temperature in Zion?
In September, the average high-temperature and low-temperature are 21.6°C and 14.7°C respectively.
What is the average humidity in September in Zion?
In September, the average relative humidity in Zion is 77%.
How much does it rain in Zion in September?
In Zion, in September, it is raining for 12.7 days, with typically 44mm of accumulated precipitation.
When it does not snow in Zion?
May through September are months without snowfall.
Does it snow in Zion in September?
In Zion, Illinois, in September, it doesn't snow. In October, it regularly snows.
How many hours of daylight does Zion have in September?
The average day length in September in Zion is 12h and 28min.
What time are sunrise and sunset in September in Zion?
On the first day of September in Zion, Illinois, sunrise is at 6:17 am and sunset at 7:24 pm. On the last day of the month, sunrise is at 6:48 am and sunset at 6:33 pm CDT.
How long on average sun shines in September in Zion?
In Zion, Illinois, the average sunshine duration in September is 9.2h.
What is the UV index reading in September in Zion?
In September, the average daily maximum UV index in Zion is 4. A UV Index reading of 3 to 5 represents a moderate vulnerability from unprotected exposure to UV radiation.
Today
Tomorrow
Long-term
YearJFMAMJJASeptemberOND
Aug
September
Oct
Average high temperature
25°C
21.6°C
14.6°C
Average low temperature
18.2°C
14.7°C
8.3°C
Average pressure
1015mbar
1017mbar
1015.8mbar
Average wind speed
11.8km/h
14.1km/h
16.9km/h
Average max. wind speed
12.6km/h
14.6km/h
18km/h
Average wind speed gusts
19.3km/h
23km/h
26.9km/h
Average humidity
79%
77%
75%
Average rainfall
68mm
44mm
48mm
Average rainfall days
15.7
12.7
12.9
Average snowfall
0mm
0mm
4mm
Average snowfall days
0
0
0.7
Average daylight
13h 5min
12h 3min
11h 0min
Average sunshine
10h 3min
9h 1min
5h 4min
Average sunshine days
11.6
13.9
14.6
Average UV index
6
4
2
Average cloud cover
27%
29%
43%
Average visibility
9km
10km
10km
Average temperature in September
Zion, IL
  • Average high temperature in September: 21.6°C

The warmest month (with the highest average high temperature) is July (25.3°C).
The month with the lowest average high temperature is January (-2.3°C).

  • Average low temperature in September: 14.7°C

The month with the highest average low temperature is July (18.5°C).
The coldest month (with the lowest average low temperature) is January (-7.6°C).

Average pressure in September
Zion, IL
  • Average pressure in September: 1017mbar

The month with the highest atmospheric pressure is January (1019.3mbar).
The month with the lowest atmospheric pressure is June (1013.2mbar).

Average wind speed in September
Zion, IL
  • Average wind speed in September: 14.1km/h

The windiest month (with the highest average wind speed) is January (19.1km/h).
The calmest month (with the lowest average wind speed) is August (11.8km/h).

Average humidity in September
Zion, IL
  • Average humidity in September: 77%

The month with the highest relative humidity is January (83%).
The months with the lowest relative humidity are October and November (75%).

Average rainfall in September
Zion, IL
  • Average rainfall in September: 44mm

The wettest months (with the highest rainfall) are June and August (68mm).
The driest month (with the least rainfall) is December (23mm).

Average rainfall days in September
Zion, IL
  • Average rainfall days in September: 12.7 days

The month with the highest number of rainy days is July (17 days).
The month with the least rainy days is February (5.2 days).

Average snowfall in September
Zion, IL
  • Average snowfall in September: 0mm

The month with the highest snowfall is February (66mm).
The months with the least snowfall are May, June, July, August and September (0mm).

Average snowfall days in September
Zion, IL
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (12.4 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Zion, 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: 9h and 1min

The months with the most sunshine are July and August (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).

Average sunshine days in September
Zion, IL
  • Average sunshine days in September: 13.9 days

The month with the most sunshine days is November (16.5 days).
The month with the least sunshine days is July (10.8 days).

Average UV index in September
Zion, 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
Zion, IL
  • Average cloud cover in September: 29

The month with the most cloud cover is January (Cloud cover 61).
The month with the least cloud cover is August (Cloud cover 27).

Average visibility in September
Zion, IL
  • Average visibility in September: 10km

The months with the highest visibility are September and October (10km).
The months with the lowest visibility are January, February, March, April, May, June, July, August, November and December (9km).

°Celsius°Fahrenheit
Share