CHICAGO | An official National Weather Service Extreme Heat Warning remains active for Chicago and Cook County, with NWS alert data listing Northern Cook, Central Cook and Southern Cook among the affected areas.
What is active now
The primary active alert is Extreme Heat Warning. NWS lists the alert severity as Severe, the urgency as Expected and the certainty as Likely. The alert became effective 30 June 2026 at 9:40 p.m. Eastern time and the listed expiration or ending time is 3 July 2026 at 1:00 a.m. Eastern time.
Coverage area
This CGN alert covers Chicago and Cook County. Conditions may vary by neighborhood, lakefront location, work site and transit corridor, and nearby counties may be under different or updated products. Readers should rely on the latest county-specific National Weather Service alert before making safety decisions.
Safety
The main risk is prolonged heat exposure, especially for older adults, people with medical conditions, people without dependable cooling, outdoor workers, unhoused residents, children and pets. Limit strenuous outdoor activity, drink water, use shade and cooling centers where available, and check on relatives and neighbors who may be vulnerable.
Official instruction
NWS urges residents to drink plenty of fluids, stay in air-conditioned rooms, stay out of the sun and check on relatives and neighbors. The warning notes that oppressive nighttime warmth can make conditions especially hazardous for older adults and people with pre-existing health conditions. Residents of Chicago can call 311 for information about cooling centers or to request well-being checks. Children and pets should never be left in unattended vehicles because interiors can become lethal within minutes.
What to watch next
This alert should be updated if the National Weather Service issues, cancels, extends or replaces the active warning. Do not rely on this article alone for emergency decisions. Keep wireless emergency alerts enabled and monitor NWS, NOAA, Chicago emergency-management information and trusted local broadcast sources.
Additional Reporting By: National Weather Service; NOAA; National Weather Service Chicago