What is the highest air pressure ever recorded in Chicago? A
What is the highest air pressure ever recorded in Chicago? A friend and I have a bet. I say it’s over 30.80 inches. My friend says it cannot possibly be that high.
— Stephanie Rodgerson, Chicago
You win the bet! On Feb. 16, 1989, Chicago recorded its highest air pressure value in the 148-year history of official weather observations: 30.98 inches of mercury recorded at O’Hare International Airport. High and low temperatures that day were 26 and 8, and there was no precipitation. Chicago’s all-time lowest air pressure value occurred March 12, 1923: 28.70 inches (temperatures that day were 41 and 31, and 0.67 inches of precipitation fell, including 0.2 inches of snow). The difference between the highest and lowest pressure readings, 2.28 inches, represents a change in elevation of 2,160 feet.