I have done everything (not necessarily in a specific order) up to getting the thermo. Problem, I cannot click the cliff (because it is dimmed) and I need to go to the cliff to use the thermo for finishing day 4. Any advice what I can do at this point?

You don't use the thermometer at the cliff, you need it at conwell woods. Do you have that location? If not, do you have all three locations marked on your map?
If that isn't the case, have you played all the tapes from the metal box and the one from the storage unit? And have you played the tape from the safe to Isaac in jail?

I have played all the tapes including the tape to isaac in jail. I don't have location for conwell woods. Do I need to open the map and check it there??

What locations are currently marked on your map?
If you already have Conwell Lake & Nature Reserve marked but not Parowan Peak you should only have to play the "Micro Cassette (Wall Safe)" tape (which you should have gotten from the church office safe) to Isaac in jail to get Parowan Peak marked on your map which in turn automatically gives you the Conwell Woods location.