September weather forecast
Hamilton, IL

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Weather in September

The first month of the autumn, September, is still a warm month in Hamilton, Illinois, with an average temperature ranging between min 57.7°F (14.3°C) and max 77.5°F (25.3°C).

Temperature

September records an average high-temperature of a still warm 77.5°F (25.3°C), indicating a minor variation from the preceding month. Hamilton anticipates an average minimum temperature of 57.7°F (14.3°C) in the month of September.

Humidity

In September, the average relative humidity is 74%.

Rainfall

In Hamilton, during September, the rain falls for 11.1 days and regularly aggregates up to 1.65" (42mm) of precipitation. Throughout the year, there are 129.9 rainfall days, and 20.71" (526mm) of precipitation is accumulated.

Snowfall

In Hamilton, Illinois, snow does not fall in May through September.

Daylight

In September, the average length of the day in Hamilton is 12h and 27min.
On the first day of the month, sunrise is at 6:33 am and sunset at 7:36 pm. On the last day of September, sunrise is at 7:01 am and sunset at 6:48 pm CDT.

Sunshine

In September, the average sunshine is 9.5h.

UV index

In September, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for the ordinary person.
Note: In September, a daily UV index of 5 turns into the following recommendations:
Exercise prevention - Warding off sunburn is urged. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in Hamilton in September?

The high-temperature, in September, in Hamilton, is 77.5°F (25.3°C), while the low-temperature averages to 57.7°F (14.3°C). In August, the average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), which combines relative humidity and air temperature, is estimated at 89.6°F (32°C).

What is the average humidity in September in Hamilton?

In Hamilton, Illinois, the average relative humidity in September is 74%.

How many days does it rain in September in Hamilton?

In Hamilton, Illinois, during September, the rain falls for 11.1 days and regularly aggregates up to 1.65" (42mm) of precipitation.

When it does not snow in Hamilton?

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

Does it snow in Hamilton in September?

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

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

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

What time are sunrise and sunset in September in Hamilton?

In September, on the first day of the month, sunrise is at 6:33 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 7:01 am and sunset at 6:48 pm CDT.

How long on average sun shines in September in Hamilton?

In Hamilton, Illinois, the average sunshine duration in September is 9.5h.

What is the UV index reading in September in Hamilton?

In Hamilton, Illinois, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium hazard to health 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
Hamilton, IL

Average temperature in September - Hamilton, IL
  • Average high temperature in September: 77.5°F

The warmest month (with the highest average high temperature) is July (83.3°F).
The month with the lowest average high temperature is January (31.3°F).

  • Average low temperature in September: 57.7°F

The month with the highest average low temperature is July (66.4°F).
The coldest month (with the lowest average low temperature) is January (19.2°F).

Average pressure in September
Hamilton, IL

Average pressure in September - Hamilton, IL
  • Average pressure in September: 30.02"Hg

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

Average wind speed in September
Hamilton, IL

Average wind speed in September - Hamilton, IL
  • Average wind speed in September: 7.5mph

The windiest months (with the highest average wind speed) are January and February (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.6mph).

Average humidity in September
Hamilton, IL

Average humidity in September - Hamilton, IL
  • Average humidity in September: 74%

The month with the highest relative humidity is July (82%).
The month with the lowest relative humidity is October (70%).

Average rainfall in September
Hamilton, IL

Average rainfall in September - Hamilton, IL
  • Average rainfall in September: 1.65"

The wettest month (with the highest rainfall) is May (2.91").
The driest month (with the least rainfall) is January (0.83").

Average rainfall days in September
Hamilton, IL

Average rainfall days in September - Hamilton, IL
  • Average rainfall days in September: 11.1 days

The month with the highest number of rainy days is May (16.8 days).
The month with the least rainy days is February (4.5 days).

Average snowfall in September
Hamilton, IL

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

The month with the highest snowfall is January (2.91").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in September
Hamilton, IL

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

The month with the highest number of snowfall days is January (7.9 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
Hamilton, IL

Average daylight in September / Average sunshine in September - Hamilton, IL
  • Average daylight in September: 12h and 2min

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 3min

The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).

Average sunshine days in September
Hamilton, IL

Average sunshine days in September - Hamilton, IL
  • Average sunshine days in September: 17.5 days

The month with the most sunshine days is December (20.4 days).
The month with the least sunshine days is June (11.5 days).

Average UV index in September
Hamilton, IL

Average UV index in September - Hamilton, IL
  • Average UV index in September: 5

The months with the highest UV index are 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
Hamilton, IL

Average cloud cover in September - Hamilton, IL
  • Average cloud cover in September: 29

The month with the most cloud cover is January (Cloud cover 54).
The months with the least cloud cover are July and August (Cloud cover 28).

Average visibility in September
Hamilton, IL

Average visibility in September - Hamilton, 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).

Hamilton, Illinois, USA

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