National Weather Service United States Department of Commerce
NOAA Weather Radio

KWO39 Chicago, 162.55 MHz

NOAA All Hazards Weather Radio station KWO39 serves marine interests on southern Lake Michigan and the Illinois and Indiana lakeshore, from a 300 Watt transmitter at the Willis Tower in downtown Chicago. The nominal effective range of the transmitter is about 40 miles. Continuous 24 hour programming is provided from the National Weather Service Chicago Forecast Office, located in southwest suburban Romeoville.

A map of the listening area is shown below, with Specific Area Message Encoder codes shown for each county. Severe weather watches and warnings are tone-alerted for all counties shaded in blue. Tone alarm tests for KWO39 occur each WEDNESDAY at approximately 11 AM.


Map of counties being served on KWO-39 County

Lake (IL)
Lake (IN)
Porter (IN)

SAME code


Signal coverage area map


Nearshore Areas (within 5 nm of shore) FIPS code
Winthrop Harbor to Wilmette Harbor 092740
Wilmette Harbor to Northerly Island 092741
Northerly Island to Calumet Harbor 092742
Calumet Harbor to Gary 092743
Gary to Burns Harbor 092744
Burns Harbor to Michigan City 092745
Winthrop Harbor to Michigan City (open waters beyond 5 NM out to midlake) 092766


Broadcast Cycle


  • Station ID Message
  • Hourly Temperature Roundup
updated between 5 and 10 min past the hour
  • Short Term Forecast
only when precipitation or active weather is near Chicagoland
  • Chicago Metro Forecast
updated 4 AM and 4 PM,, or as needed
  • Open Lakes Forecast for Lake Michigan
updated 3 AM, 9 AM, 3 AM and 9 PM
  • Nearshore Marine Forecast for Illinois and Indiana Shores
updated 4 AM, 10 AM, 4 PM and 9 PM
  • Marine Observations
updated every hour
  • Water Temperatures
updated everyday at 9 AM
  • Severe Weather and other special programming during "active" weather