Illinois alerts

Cook County, Illinois weather alerts

2 National Weather Service alerts are in force for Cook County: a flood warning and a beach hazards statement.

Checked Sun, Sep 20, 2026, 2:25 PM CDT. Times are Central Daylight Time.

Cook County forecastLive radar here

Warnings on the map

Every watch, warning and advisory the National Weather Service has in force over Cook County, Illinois. Open it for the live map, where it pans and zooms.

Every watch, warning and advisory the National Weather Service has in force over Cook County, Illinois Open the live map with warnings and watches

Map layer from NOAA National Weather Service. Boundaries from the Iowa Environmental Mesonet.

Alerts in force2

Every product in force for Cook County, worst first, with its full text.

Flood Warning

Severe

Flood Warning issued September 20 at 9:45AM CDT until September 21 at 1:00AM CDT by NWS Chicago IL

Issued Until 10 hr 34 min left

Areas Cook, IL; Lake, IN

Full text

...The Flood Warning continues for the following rivers in Illinois...Indiana... Little Calumet River at Munster (Hohman Avenue) affecting Lake IN and Cook Counties. For the Little Calumet River...including South Holland, Munster (Hohman Avenue)...Minor flooding is forecast. * WHAT...Minor flooding is forecast. * WHERE...Little Calumet River from IN-912 in Hammond downstream to confluence with Thorn Creek in South Holland, including the Munster (Hohman Avenue) gauge. * WHEN...Until late tonight. * IMPACTS...At 12.5 feet, Most areas outside of the levee-protected area are inundated in Hammond and Munster. * ADDITIONAL DETAILS... - At 9:00 AM CDT Sunday the stage was 9.3 feet. - Forecast...The river is expected to briefly rise and crest to around flood stage of 12.0 feet late this afternoon into early evening. It will then fall below flood stage late this evening. - Flood stage is 12.0 feet. - http://www.weather.gov/safety/flood

What to do

A Flood Warning means water levels above flood stage are imminent or may already be occurring. Persons along rivers and streams in the warned area should take immediate precautions to protect life and property. These forecasts are based on observed precipitation as well as forecast precipitation 24 hours into the future. Changes to the rainfall forecast, or any additional rainfall after 24 hours, may cause changes to these river forecasts. Additional information is available at www.weather.gov. The next statement will be issued by late tonight.

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Beach Hazards Statement

Moderate

Beach Hazards Statement issued September 20 at 10:23AM CDT until September 22 at 7:00PM CDT by NWS Chicago IL

Issued Until 2 days left

Areas Lake, IL; Northern Cook, IL; Central Cook, IL

Full text

* WHAT...High wave action and dangerous currents expected at Lake Michigan beaches. Waves 7 to 10 ft expected. * WHERE...Lake IL, Northern Cook and Central Cook Counties. * WHEN...Through Tuesday evening. * IMPACTS...Swimming conditions will be life threatening, especially for inexperienced swimmers.

What to do

Remain out of the water to avoid dangerous swimming conditions and do not venture out onto piers, jetties, breakwalls, or other shoreline structures.

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The past year in Cook County

In the past year the National Weather Service issued 309 alerts for Cook County, including 66 severe thunderstorm warnings, 40 flood warnings, 17 flash flood warnings and 10 tornado warnings.

ProductIssuedMost recent
Severe Thunderstorm Warning66Aug 12, 2026
Flood Warning40Sep 20, 2026
Flash Flood Warning17Aug 1, 2026
Tornado Warning10Aug 11, 2026
Winter Storm Warning4Jan 30, 2026
High Wind Warning3Jun 11, 2026
Extreme Heat Warning2Sep 3, 2026
Freeze Warning2Apr 20, 2026
Extreme Cold Warning1Jan 23, 2026
Lakeshore Flood Warning1Aug 11, 2026
Red Flag Warning1Feb 18, 2026
Snow Squall Warning1Jan 14, 2026
Flood Watch24Sep 20, 2026
Severe Thunderstorm Watch17Aug 21, 2026
Tornado Watch4Jun 11, 2026
Winter Storm Watch3Jan 31, 2026
Extreme Cold Watch1Jan 23, 2026
Extreme Heat Watch1Jun 29, 2026
Fire Weather Watch1Feb 18, 2026
Freeze Watch1Apr 20, 2026
High Wind Watch1Mar 13, 2026
Flood Advisory50Sep 20, 2026
Dense Fog Advisory10Aug 13, 2026
Wind Advisory10Jun 28, 2026
Winter Weather Advisory10Mar 15, 2026
Cold Weather Advisory4Jan 26, 2026
Frost Advisory4May 7, 2026
Heat Advisory4Sep 4, 2026
Beach Hazard Statement16Sep 20, 2026

Warnings issued

  1. Flood Warning
  2. Extreme Heat Warning
  3. Flood Warning
  4. Severe Thunderstorm Warning
  5. Flood Warning
  6. Lakeshore Flood Warning
  7. Tornado Warning
  8. Tornado Warning
  9. Severe Thunderstorm Warning
  10. Severe Thunderstorm Warning
  11. Tornado Warning
  12. Severe Thunderstorm Warning
  13. Severe Thunderstorm Warning
  14. Severe Thunderstorm Warning
  15. Severe Thunderstorm Warning
  16. Severe Thunderstorm Warning
  17. Flood Warning
  18. Flood Warning
  19. Flood Warning
  20. Flood Warning
  21. Flood Warning
  22. Flash Flood Warning
  23. Flood Warning
  24. Severe Thunderstorm Warning
  25. Severe Thunderstorm Warning
  26. Severe Thunderstorm Warning
  27. Flood Warning
  28. Severe Thunderstorm Warning
  29. Severe Thunderstorm Warning
  30. Flash Flood Warning
  31. Tornado Warning
  32. Tornado Warning
  33. Severe Thunderstorm Warning
  34. Severe Thunderstorm Warning
  35. Severe Thunderstorm Warning
  36. Severe Thunderstorm Warning
  37. Tornado Warning
  38. Flash Flood Warning
  39. Severe Thunderstorm Warning
  40. Severe Thunderstorm Warning
  41. Flood Warning
  42. Flood Warning
  43. Flood Warning
  44. Flood Warning
  45. Flash Flood Warning
  46. Flash Flood Warning
  47. Flash Flood Warning
  48. Flash Flood Warning
  49. Severe Thunderstorm Warning
  50. Flash Flood Warning
  51. Flood Warning
  52. Flood Warning
  53. Flood Warning
  54. Flash Flood Warning
  55. Flash Flood Warning
  56. Flash Flood Warning
  57. Severe Thunderstorm Warning
  58. Severe Thunderstorm Warning
  59. Severe Thunderstorm Warning
  60. Severe Thunderstorm Warning

And 88 earlier warnings.

Every alert, most recent first
  1. Flood Watch
  2. Flood Watch
  3. Flood Watch
  4. Beach Hazard Statement
  5. Flood Warning
  6. Flood Advisory
  7. Flood Watch
  8. Beach Hazard Statement
  9. Beach Hazard Statement
  10. Flood Advisory
  11. Beach Hazard Statement
  12. Beach Hazard Statement
  13. Heat Advisory
  14. Extreme Heat Warning
  15. Heat Advisory
  16. Heat Advisory
  17. Beach Hazard Statement
  18. Severe Thunderstorm Watch
  19. Flood Watch
  20. Flood Advisory
  21. Flood Watch
  22. Flood Warning
  23. Dense Fog Advisory
  24. Flood Advisory
  25. Flood Advisory
  26. Severe Thunderstorm Warning
  27. Severe Thunderstorm Watch
  28. Flood Warning
  29. Lakeshore Flood Warning
  30. Flood Advisory
  31. Tornado Warning
  32. Tornado Warning
  33. Severe Thunderstorm Warning
  34. Severe Thunderstorm Warning
  35. Tornado Warning
  36. Severe Thunderstorm Watch
  37. Severe Thunderstorm Watch
  38. Severe Thunderstorm Warning
  39. Flood Watch
  40. Severe Thunderstorm Watch

The 40 most recent of 309.

From the Iowa Environmental Mesonet’s archive of NWS watches, warnings and advisories (VTEC), by the county’s own code and the forecast zones inside it. Each date links to the event at the IEM.

Nearby

The counties around Cook County, with what is in force in each.

What this means

Warning
The hazard is happening or about to. Act now: a tornado warning means take shelter, a flash flood warning means move to higher ground.
Watch
Conditions favor the hazard. Nothing is happening yet; have a plan and be ready to act if a warning follows.
Advisory
A hazard that is less serious than a warning but can still cause trouble, such as dense fog, heat or light ice.
Statement
Information about weather that does not yet meet a warning: a strong storm, a hydrologic update, or a special weather statement.

Severity (extreme, severe, moderate, minor) is the rating the issuing office gives each product. More on the difference: tornado watch vs. tornado warning. Alerts come from the National Weather Service; follow its instructions and your local officials.

Sources

Alerts from the National Weather Service's public feed, read afresh every minute, and matched to counties and zones by their UGC codes. Warnings from outside the United States come from each country's own meteorological service. Follow the issuing office's instructions and your local officials.