Tornadoes, microbursts and 100-mph winds; DeKalb is no stranger to these forces of nature.

A few years ago, NIU meteorologist Gilbert Sebenste joined with Tom Grazulis, leading tornado climatologist and founder of The Tornado Project, to determine DeKalb’s tornado vulnerability.

Together, Sebenste and Grazulis concluded that NIU would be hit by a tornado every 50 years, while DeKalb would be hit every 30 years.

Their predictions were more than spot on. In the last 30 years, DeKalb has been hit twice by tornados according to Sebenste and a U.S. tornado history database at tornadohistoryproject.com.

“I’ve seen three tornados touch down while sitting in my office high atop Davis Hall,” Sebenste said.

In 1982, a tornado started southwest of DeKalb and hit the northwest side of campus, causing minor damage before passing through the Amber Manor apartment complex and finally dissipating. This tornado ranked F1 on the Fujita Scale, a scale measuring tornado intensity after it’s passed through a man-made structure.

Years later, in 1996, another F1 tornado severely damaged a weakly built home in DeKalb, according to Sebenste. Sebenste did a damage survey on this tornado, and although the tornado caused minor damage to a secluded area of the city, it was enough to cause worry.

“There is a severe weather threat at NIU, and we take that very seriously,” Sebenste said.

The wailing sirens often heard while sitting in class on particularly gusty days are NIU’s way of keeping campus safe. With over 200 weather radios across campus, including residence halls, alerting faculty and students of severe weather, DeKalb’s weather is no joke.

After extensive research, Sebenste’s findings have shown that DeKalb typically sees two severe thunderstorms every year with hail droplets reaching a quarter inch in diameter and wind gusts up to 50 mph. DeKalb experiences 70-mph winds once every three years, 80-mph winds once every five years and 100-mph winds once every decade, according to Sebenste.

“People think Illinois is not in tornado alley, but they’re very much mistaken,” said Sebenste as he explained the main causes of DeKalb’s severe weather history.

As the cold, dry air from Canada hits the warm, moist air from the Gulf of Mexico, it produces thunderstorms with enough wind shear to sometimes develop into tornadoes. It’s the unique geography of the U.S. that puts the Midwest into the center of severe weather, and it doesn’t help that DeKalb has minimal geographic barriers to prevent such storms.

Illinois has been documented by disastercenter.com as ranking sixth in the nation for tornado frequencies as listed per state and ranks fifth in tornado frequencies per square mile.