Harrisburg, IL Climate

Harrisburg, IL has a humid continental climate with hot, humid summers and cold winters. The city enjoys four distinct seasons throughout the year and often experiences moderate snowfall during the winter months. Temperatures in summertime can reach up to the mid-80s Fahrenheit (about 30 degrees Celsius), while winter temperatures average around 25°F (-4°C). Precipitation is quite frequent throughout the year, especially during spring and fall when you can expect to see plenty of rain and thunderstorms.

Harrisburg, Illinois gets 49 inches of rain, on average, per year. The US average is 38 inches of rain per year.

Harrisburg averages 8 inches of snow per year. The US average is 28 inches of snow per year.

On average, there are 197 sunny days per year in Harrisburg. The US average is 205 sunny days.

Harrisburg gets some kind of precipitation, on average, 102 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 88 degrees
Winter Low: the January low is 22
Rain: averages 49 inches of rain a year
Snow: averages 8 inches of snow a year

Bestplaces Comfort Index

The annual BestPlaces Comfort Index for Harrisburg is 7.3 (10=best), which means it is one of the most pleasant places in Illinois.

7.7 Summer - 5.7 Winter

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

Climate	Harrisburg, Illinois	United States
	48.5 in.	38.1 in.
	8.2 in.	27.8 in.
	102.2 days	106.2 days
	197 days	205 days
	87.5°	85.8°
	22.4°	21.7°
	7.3	7
	4.1	4.3
	394 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 Harrisburg with an average high temperature of 87.5°, which ranks it as warmer than most places in Illinois. In Harrisburg, there are 3 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Harrisburg are May, September and June.

In Harrisburg, there are 29.7 days annually when the high temperature is over 90°, which is hotter than most places in Illinois.

January has the coldest nighttime temperatures for Harrisburg with an average of 22.4°. This is one of the warmest places in Illinois.

In Harrisburg, there are 101.9 days annually when the nighttime low temperature falls below freezing, which is warmer than most places in Illinois.

In Harrisburg, there are 2.1 days annually when the nighttime low temperature falls below zero°, which is warmer than most places in Illinois.

The humidity can be uncomfortably heavy or close in Harrisburg during the summer months. July is the most humid month, though humidity is low for most of the year. July, August and June are the three most humid months in Harrisburg.

May is the wettest month in Harrisburg with 5.5 inches of rain, and the driest month is August with 3.1 inches. The wettest season is Summer with 30% of yearly precipitation and 23% occurs in Spring, which is the driest season. The annual rainfall of 48.5 inches in Harrisburg means that it is one of the wettest places in Illinois.

April is the rainiest month in Harrisburg with 10.6 days of rain, and August is the driest month with only 6.5 rainy days. There are 102.2 rainy days annually in Harrisburg, which is less rainy than most places in Illinois. The rainiest season is Summer when it rains 31% of the time and the driest is Winter with only a 23% chance of a rainy day.

An annual snowfall of 8.2 inches in Harrisburg means that it is one of the least snowy places in Illinois. February is the snowiest month in Harrisburg with 3.0 inches of snow, and 4 months of the year have significant snowfall.