Illinois Beach State Park Water Temperature

4.8°C / 40.6°F

The sea at Illinois Beach State Park feels very-cold so don't forget to pack your wetsuit!

Average Sea Temp for Illinois Beach State Park

The chart and table below are the sea temperature averages for Illinois Beach State Park calculated from over twenty years of oceanographic data. As above the water temperatures given are for sea surface temperature (SST) which is most relevant to recreational users.

Illinois Beach State Park sea temperature in degrees Celsius and Fahrenheit
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 4 3 3 4 6 12 19 22 20 14 9 5
°F 39 37 37 38 43 54 67 71 67 57 48 42