Chicago woke up shivering on Monday, April 20, 2026, with clear skies and a brisk 37°F at Midway Airport and a Frost Advisory in place for central Cook County through 9 a.m. The cold start is no joke for backyard growers: sensitive outdoor plants could take a hit if they are left exposed, so potted plants should be brought inside or covered before the sun gets higher. After the frosty wake-up call, the city can expect a bright but cool day, with a high near 50°F and light east-southeast breezes.
Frost Advisory And Plant Care
Under the advisory, temperatures are dipping into the low to mid 30s across the near-west suburbs, with patchy frost possible even in parts of the city. Anyone with early blooms or tender starts is being urged to take quick steps to protect them. Tonight is expected to turn breezy, with south-southeast winds around 10 to 15 mph and gusts up to 25 mph, setting the stage for a sharp Tuesday warm-up to around 74°F and gusts near 30 mph. These conditions are detailed in the local forecast from the National Weather Service.
Late-Week Rain Chances
Another weather system is expected to move in later in the week, bringing a chance for more widespread showers and thunderstorms from late Thursday into Friday. Forecasters currently see the severe threat as limited, but are still advising people with outdoor plans to keep an eye on updates. Earlier this month, heavy rain left the region primed for extra runoff if strong downpours return. For context on that recent rainfall and what additional storms could mean for streets and sewer capacity, see reporting from WTTW.
