September weather forecast
Eureka, IL

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Weather in September

September, the first month of the autumn in Eureka, is still a warm month, with an average temperature ranging between min 57°F (13.9°C) and max 75.7°F (24.3°C).

Temperature

The transition into September reveals an average high-temperature of a still warm 75.7°F (24.3°C), mirroring a close resemblance to August. In Eureka, September is marked by an average low-temperature of 57°F (13.9°C).

Humidity

In September, the average relative humidity is 76%.

Rainfall

In Eureka, in September, during 12.4 rainfall days, 1.81" (46mm) of precipitation is typically accumulated. Throughout the year, there are 147.1 rainfall days, and 24.17" (614mm) of precipitation is accumulated.

Snowfall

May through September are months without snowfall.

Daylight

In Eureka, Illinois, 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, in Eureka, sunrise is at 6:53 am and sunset at 6:40 pm CDT.

Sunshine

The average sunshine in September 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 vulnerability from exposure to the Sun's UV rays for the average person.
Note: A daily high UV index of 4 in September leads to these guidelines:
Ensure safety - Recommendations to avert sunburn are presented. Avoiding the Sun during its peak radiation time around midday is a healthy practice. Stay sun-safe with clothing that is both closely woven and worn loosely.
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 Eureka?

The high-temperature, in September, in Eureka, records 75.7°F (24.3°C), while the low-temperature is 57°F (13.9°C). In July, the average heat index (a.k.a. 'felt air temperature', 'real feel'), which combines relative humidity and air temperature, is evaluated at 87.8°F (31°C).

What is the average humidity in September in Eureka?

In September, the average relative humidity is 76%.

How much does it rain in Eureka in September?

In Eureka, during September, the rain falls for 12.4 days and regularly aggregates up to 1.81" (46mm) of precipitation.

When it does not snow in Eureka?

May through September are months without snowfall in Eureka.

Does it snow in Eureka in September?

In Eureka, Illinois, in September, it doesn't snow. In October, it regularly snows.

What is the average length of the day in September in Eureka?

The average day length in September in Eureka, Illinois, is 12h and 27min.

When is the sunrise / sunset in September in Eureka?

On the first day of September in Eureka, Illinois, sunrise is at 6:24 am and sunset at 7:28 pm. On the last day of the month, sunrise is at 6:53 am and sunset at 6:40 pm CDT.

How long on average sun shines in September in Eureka?

The average sunshine duration in September in Eureka is 9.2h.

How high is the UV index in September in Eureka?

In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate health threat 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
Eureka, IL

Average temperature in September - Eureka, IL
  • Average high temperature in September: 75.7°F

The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (30.4°F).

  • Average low temperature in September: 57°F

The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (18.5°F).

Average pressure in September
Eureka, IL

Average pressure in September - Eureka, IL
  • Average pressure in September: 30.03"Hg

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

Average wind speed in September
Eureka, IL

Average wind speed in September - Eureka, IL
  • Average wind speed in September: 7.6mph

The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).

Average humidity in September
Eureka, IL

Average humidity in September - Eureka, IL
  • Average humidity in September: 76%

The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (72%).

Average rainfall in September
Eureka, IL

Average rainfall in September - Eureka, IL
  • Average rainfall in September: 1.81"

The wettest month (with the highest rainfall) is May (3.11").
The driest month (with the least rainfall) is December (1.22").

Average rainfall days in September
Eureka, IL

Average rainfall days in September - Eureka, IL
  • Average rainfall days in September: 12.4 days

The month with the highest number of rainy days is May (17.9 days).
The month with the least rainy days is January (5.8 days).

Average snowfall in September
Eureka, IL

Average snowfall in September - Eureka, IL
  • Average snowfall in September: 0"

The months with the highest snowfall are January and February (2.8").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in September
Eureka, IL

Average snowfall days in September - Eureka, IL
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (11 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
Eureka, IL

Average daylight in September / Average sunshine in September - Eureka, IL
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).

  • Average sunshine in September: 9h and 1min

The month with the most sunshine is June (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).

Average sunshine days in September
Eureka, IL

Average sunshine days in September - Eureka, IL
  • Average sunshine days in September: 15.8 days

The month with the most sunshine days is November (18.4 days).
The month with the least sunshine days is July (9 days).

Average UV index in September
Eureka, IL

Average UV index in September - Eureka, IL
  • Average UV index in September: 4

The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in September
Eureka, IL

Average cloud cover in September - Eureka, IL
  • Average cloud cover in September: 30

The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is September (Cloud cover 30).

Average visibility in September
Eureka, IL

Average visibility in September - Eureka, 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).

Eureka, Illinois, USA

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