Steam can, and should, be superheated for use in steam turbines. Temperature of superheated steam is in the 600 degreeF range. The old steam boilers used on UL cargo ships had inner stage steam running through it in excess of 600 degrees. Steam becomes invisible at that temperature, which makes steam leaks extremely dangerous.
A mere 1,005 F in utility boilers and turbines.
So, obviously, Lake Michigan is invisible.