What was the weather like in the days before and after Chicago’s all-time record low of minus 27?

Dear Tom,

What was the weather like in the days before and after Chicago’s all-time record low of minus 27?

Thanks,
William Drezdzon,
Des Plaines

Dear William,

Chicago weather historian Frank Wachowski checked out January 1985 when the city logged its all-time record low of 27 below on the 20th. In mid-January temperatures were running a bit colder than normal with highs in the low/mid 20s and lows around 10. On January 18 after a high of 24, a strong arctic cold front sent temperatures on a steep decline. By midnight the mercury had fallen to 10 and it continued to fall steadily reaching minus 23 by midnight. The drop continued until the record low of minus 27 was reached on the 20th shortly after 6am. The city slowly emerged from the deep freeze finally reaching 30 degrees on the 27th, but temperatures did not break freezing until a 36 high on February 17.