Summit, IL Climate

Summit, IL has a humid continental climate typified by hot, humid summers and cold winters. In the summer months, temperatures tend to reach into the high 80s with high humidity levels. Winters in Summit are relatively cold with temperatures dropping to the teens or twenties and receiving an average of 20-30 inches of snow throughout the season. Despite its location in a temperate region, Summit experiences four distinct seasons with spring and fall bringing mild temperatures and moderate rainfall.

Summit, Illinois gets 39 inches of rain, on average, per year. The US average is 38 inches of rain per year.

Summit averages 32 inches of snow per year. The US average is 28 inches of snow per year.

On average, there are 189 sunny days per year in Summit. The US average is 205 sunny days.

Summit gets some kind of precipitation, on average, 124 days per year. Precipitation is rain, snow, sleet, or hail that falls to the ground. In order for precipitation to be counted you have to get at least .01 inches on the ground to measure.

Weather Highlights

Summer High: the July high is around 84 degrees
Winter Low: the January low is 20
Rain: averages 39 inches of rain a year
Snow: averages 32 inches of snow a year

Bestplaces Comfort Index

The annual BestPlaces Comfort Index for Summit is 7.0 (10=best), which means it is about average compared to other places in Illinois.

8.9 Summer - 4.7 Winter

September, June and August are the most pleasant months in Summit, while January and December are the least comfortable months.

Climate	Summit, Illinois	United States
	39.1 in.	38.1 in.
	31.9 in.	27.8 in.
	124.3 days	106.2 days
	189 days	205 days
	84.1°	85.8°
	19.6°	21.7°
	7	7
	3.6	4.3
	614 ft.	2443 ft.

Climate

YOU SHOULD KNOW

Many people confuse weather and climate but they are different. Weather is the conditions of the atmosphere over a short period of time, and climate is how the atmosphere is over long periods of time.

Weather is how the atmosphere is behaving and its effects upon life and human activities. Weather can change from minute-to-minute. Most people think of weather in terms of temperature, humidity, precipitation, cloudiness, brightness, visibility, wind, and atmospheric pressure.

Climate is the description of the long-term pattern of weather in a place. Climate can mean the average weather for a particular region and time period taken over 30 years. Climate is the average of weather over time.

July is the hottest month for Summit with an average high temperature of 84.1°, which ranks it as cooler than most places in Illinois. In Summit, there are 4 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Summit are June, September and August.

In Summit, there are 13.8 days annually when the high temperature is over 90°, which is cooler than most places in Illinois.

January has the coldest nighttime temperatures for Summit with an average of 19.6°. This is warmer than most places in Illinois.

In Summit, there are 101.5 days annually when the nighttime low temperature falls below freezing, which is warmer than most places in Illinois.

In Summit, there are 3.7 days annually when the nighttime low temperature falls below zero°, which is warmer than most places in Illinois.

The humidity is usually comfortable in Summit but some summer months can be sticky or muggy. July is the most humid month, though humidity is low for most of the year. The most humid months are July, August and June.

August is the wettest month in Summit with 4.3 inches of rain, and the driest month is February with 1.9 inches. The wettest season is Autumn with 31% of yearly precipitation and 17% occurs in Spring, which is the driest season. The annual rainfall of 39.1 inches in Summit means that it is about average compared to other places in Illinois.

May is the rainiest month in Summit with 11.7 days of rain, and February is the driest month with only 8.3 rainy days. There are 124.3 rainy days annually in Summit, which is one of the rainiest places in Illinois. The rainiest season is Summer when it rains 27% of the time and the driest is Spring with only a 24% chance of a rainy day.

An annual snowfall of 31.9 inches in Summit means that it is snowier than most places in Illinois. January is the snowiest month in Summit with 10.5 inches of snow, and 6 months of the year have significant snowfall.