Yes

you do need a jacket based on the weather in Chicago, IL 60660, USA 1 second ago

Why? Because it's quite chilly.
47°F8°C & Mostly Clear

Wind is 12 mph20 km/h from the NW, gusting to 25 mph40 km/h
April 20
12am45°F7°C13 mph22 km/h NWMostly Clear
1am42°F6°C13 mph21 km/h NWMostly Clear
2am40°F4°C13 mph20 km/h NWClear
3am38°F3°C12 mph19 km/h NWClear
4am37°F3°C12 mph19 km/h NWClear
5am35°F2°C12 mph19 km/h WClear
6am34°F1°C12 mph19 km/h WClear
7am34°F1°C12 mph19 km/h WClear
8am34°F1°C12 mph19 km/h WClear
9am36°F2°C13 mph21 km/h WClear
10am38°F3°C13 mph22 km/h NWClear
11am40°F5°C13 mph21 km/h NWMostly Clear
DateLowHighWindDayNight
April 1941°F5°C57°F14°C10 mph16 km/h from WMostly ClearMostly Clear
April 2034°F1°C49°F9°C12 mph19 km/h from NWPartly CloudyPartly Cloudy
April 2136°F2°C57°F14°C8 mph13 km/h from WMostly ClearMostly Clear
April 2241°F5°C64°F18°C10 mph17 km/h from SWPartly CloudyCloudy
April 2346°F8°C61°F16°C14 mph22 km/h from WRainPartly Cloudy
April 2437°F3°C47°F8°C12 mph19 km/h from NEMostly ClearPartly Cloudy
April 2535°F1°C55°F13°C8 mph12 km/h from EMostly ClearMostly Cloudy

Yes

Low of 34°F1°C, High of 48°F9°C
Wind: 12 mph19 km/h
Precipitation: None

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