September weather forecast
Mount Erie, IL

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Weather in September

The first month of the autumn, September, is still a warm month in Mount Erie, Illinois, with temperature in the range of an average high of 79°F (26.1°C) and an average low of 60.4°F (15.8°C).

Temperature

The arrival of September marks a slight shift to an average high-temperature of a still moderately hot 79°F (26.1°C) from August's 83.8°F (28.8°C). Throughout September, Mount Erie records an average temperature of 60.4°F (15.8°C) at night.

Humidity

In Mount Erie, the average relative humidity in September is 74%.

Rainfall

September is the month with the least rainfall. Rain falls for 13.5 days and accumulates 2.05" (52mm) of precipitation.

Snowfall

May through October are months without snowfall.

Daylight

The average length of the day in September in Mount Erie is 12h and 25min.
On the first day of September, sunrise is at 6:22 am and sunset at 7:22 pm. On the last day of the month, sunrise is at 6:48 am and sunset at 6:36 pm CDT.

Sunshine

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 health hazard from unprotected exposure to Sun's UV rays for average individuals.
Note: An average maximum UV index of 5 in September leads to these recommendations:
Exercise prevention - Protecting skin and eyes from harm is required. To protect against the Sun's most potent rays, avoid direct exposure around midday. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears.
Updated: Jul 26, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures?

The average high-temperature, in September, in Mount Erie, is 79°F (26.1°C), while the average low-temperature is 60.4°F (15.8°C). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which takes the relative humidity and factors it into the air temperature reading, in August is calculated to be 93.2°F (34°C).

What is the average humidity in September?

In September, the average relative humidity is 74%.

What is the driest month?

September is the month with the least rainfall in Mount Erie. Rain falls for 13.5 days and accumulates 2.05" (52mm) of precipitation.

How much does it rain in September?

In September, the rain falls for 13.5 days. Throughout September, 2.05" (52mm) of precipitation is accumulated.

When it does not snow?

In Mount Erie, snow does not fall in May through October.

What is the average length of the day in September?

In Mount Erie, the average day length in September is 12h and 25min.

When is the sunrise / sunset in September in Mount Erie?

In September, on the first day of the month, sunrise is at 6:22 am and sunset at 7:22 pm. On the last day of the month, sunrise is at 6:48 am and sunset at 6:36 pm CDT.

How many hours of sunshine does Mount Erie have in September?

The average sunshine duration in September is 9.1h.

How high is the UV index in September?

In Mount Erie, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate vulnerability from exposure to Sun's UV rays.
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
Mount Erie, IL

Average temperature in September - Mount Erie, IL
  • Average high temperature in September: 79°F

The warmest month (with the highest average high temperature) is July (85.1°F).
The month with the lowest average high temperature is January (37.8°F).

  • Average low temperature in September: 60.4°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 (25°F).

Average pressure in September
Mount Erie, IL

Average pressure in September - Mount Erie, 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 (29.94"Hg).

Average wind speed in September
Mount Erie, IL

Average wind speed in September - Mount Erie, IL
  • Average wind speed in September: 6.7mph

The windiest months (with the highest average wind speed) are February and March (9.9mph).
The calmest month (with the lowest average wind speed) is July (5.9mph).

Average humidity in September
Mount Erie, IL

Average humidity in September - Mount Erie, IL
  • Average humidity in September: 74%

The months with the highest relative humidity are May and July (79%).
The month with the lowest relative humidity is October (70%).

Average rainfall in September
Mount Erie, IL

Average rainfall in September - Mount Erie, IL
  • Average rainfall in September: 2.05"

The wettest month (with the highest rainfall) is April (4.96").
The driest month (with the least rainfall) is September (2.05").

Average rainfall days in September
Mount Erie, IL

Average rainfall days in September - Mount Erie, IL
  • Average rainfall days in September: 13.5 days

The month with the highest number of rainy days is May (19.8 days).
The month with the least rainy days is January (8.7 days).

Average snowfall in September
Mount Erie, IL

Average snowfall in September - Mount Erie, IL
  • Average snowfall in September: 0"

The months with the highest snowfall are January and February (2.01").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Mount Erie, IL

Average snowfall days in September - Mount Erie, IL
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (6.7 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
Mount Erie, IL

Average daylight in September / Average sunshine in September - Mount Erie, 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 month with the most sunshine is June (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).

Average sunshine days in September
Mount Erie, IL

Average sunshine days in September - Mount Erie, IL
  • Average sunshine days in September: 14.5 days

The month with the most sunshine days is October (17.9 days).
The month with the least sunshine days is May (9 days).

Average UV index in September
Mount Erie, IL

Average UV index in September - Mount Erie, 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, February, November and December (UV index 2).

Average cloud cover in September
Mount Erie, IL

Average cloud cover in September - Mount Erie, IL
  • Average cloud cover in September: 29

The months with the most cloud cover are January and February (Cloud cover 51).
The months with the least cloud cover are June and August (Cloud cover 28).

Average visibility in September
Mount Erie, IL

Average visibility in September - Mount Erie, 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).

Mount Erie, Illinois, USA

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