Chicagoans will experience a shift in the weather as they move away from today's comfortable warmth to a more oppressive humidity starting Sunday. According to the detailed forecast, the city will see mostly sunny skies with a high near 79 degrees, but expect the comfort to be short-lived. The National Weather Service Chicago/Romeoville IL has issued a Hazardous Weather Outlook, pointing out that no immediate threats loom for today and tonight. However, looking ahead from Sunday through Friday, there's a "Limited Thunderstorm Risk" and for a period, a "Limited Excessive Heat Risk".

Humid weather is on the horizon, and with it comes a surge in temperatures—as high as a sweltering 96 degrees by Monday, potentially pushing heat indices to surpass the 100-degree mark, per the weather outlook. Residents should be prepared for "periodic chances for isolated to scattered showers/storms" according to an update from the weather service shared via X, thus signaling a potentially erratic week of weather ahead.

Sunday night seems promising as well, with mostly clear skies and a low around 76 degrees, but it's the lead into the hotter days to follow. As June approaches, the forecast includes a mix of showers and thunderstorms in the afternoon, with a partly sunny embrace, projected highs resting near the 91-degree mark. 

While no immediate hazardous conditions threaten the boating enthusiasts on Lake Michigan, the National Weather Service cautions that the "Limited Thunderstorm Risk" remains through the upcoming week for the Illinois and Indiana nearshore waters, and heat-safety measures should be a priority for everyone venturing outdoors.