Snowfall trends vary by region, but in Illinois, there has been a decline in the amount of snow that falls each year. Illinois snowfall records start in 1902; prior, however, there was not a long history of snowfall records. Let’s look at the environmental impacts on snowfall and the snowfall trends over the years.
PSA: It is important to note that snow measurement methods have changed over the years, which impacts the data we collect and research today. While reading this article, keep in mind that different measurement methods affect data findings and snowfall records.
To continue, two environmental factors that affect snowfall trends are the rate of precipitation and climate change. According to the Environmental Protection Agency, “One reason for the decline in total snowfall is because more winter precipitation is falling in the form of rain instead of snow. Nearly 80 percent of the stations across the contiguous 48 states have experienced a decrease in the proportion of precipitation falling as snow” (Climate Change Indicators: Snowfall 2023).
The figure below represents the change in total snowfall in the contiguous 48 states from 1930 to 2007(Climate Change Indicators: Snowfall 2023).
While it is known that the proportion of winter precipitation that falls as snow across the United States is decreasing, let’s examine Illinois specifically.
The information below gives yearly information about snowfall in central Illinois up to the year 2020, providing an insight into average snowfall as well as how many days it snows.
Current average total snowfall for a year:
- Champaign: 20.8 in, 17.4 days
- Bloomington: 6.5 in, 5 days
- Decatur: 13.6 in, 9.6 days
- Springfield: 21.8 in, 16.3 days
The information below is the average annual temperatures for cities in central Illinois.
Current average yearly temperatures:
- Champaign: 62 F (High), 43 F (Low)
- Bloomington: 60 F (High), 40 F (Low)
- Decatur: 62 F (High), 44 F (Low)
- Springfield: 64 F (High), 44 F (Low)
When we compare this information to snowfall trends in the past, there are clear differences. The Illinois State Climatologist website states, “Snowfall amounts dropped steeply with less year-to-year variability for much of the 1980s and into the early 2000s. However, snowfall amounts in the last 6 winters have been more variable with the winter of 2014 being about as snowy as the late 1970s.”
In 1979, Illinois experienced its snowiest winter, with 44.5 inches of snow (Snowfall Trends, Illinois State Climatologist). This played a significant role in the 1960s and 1970s, which were two of the snowiest decades in Illinois since 1900. As stated above, the winter of 2014 was similar to the blizzard in the late ‘70s. However, we must also consider that a lot has changed environmentally and climate-wise in the past decade.
Ultimately, it is essential to remember that different measurement methods have been used over the decades, which is why only a few scientific papers have been published on snowfall trends. With the knowledge we do have, however, we can look at broad-scale snowfall trends and data.
If you would like to access more information on Illinois annual snowfalls, Illinois State Climatologist has a great one linked here.
References
Average annual temperatures in Illinois. Average Temperatures in Illinois – Current Results. (n.d.). https://www.currentresults.com/Weather/Illinois/average-annual-temperatures.php
Environmental Protection Agency. (2023). Climate Change Indicators: Snowfall. EPA. https://www.epa.gov/climate-indicators/climate-change-indicators-snowfall#:~:text=One%20reason%20for%20the%20decline%20in%20total%20snowfall,%28see%20Figure%202%29.%20Snowfall%20trends%20vary%20by%20region.
Snowfall trends. Illinois State Climatologist. (n.d.). https://stateclimatologist.web.illinois.edu/snowfall-trends/
