While spring is a beautiful time in Chicago, cool and rainy weather can persist well into May. For the first week of May, normal temperatures* range from a low of 44 degrees (Fahrenheit) to a high of 68. May brings an average of 3.7 inches of rain* in our fair city, but sunny days abound.
In other words, check the forecast before you travel, bring an umbrella or raincoat, and come prepared with warm layers. Even if you are greeted upon arrival by warmth and sunshine, you will likely need that sweater to endure air-conditioned interiors.
*Climate Calendar [Internet]. Champaign (IL): Midwestern Regional Climate Center.  – [cited 2019 Feb 4]. Available from: https://mrcc.illinois.edu/mw_climate/calendars/calWelcome.jsp.