Temp sender and voltage stabiliser (feeding the gauge) as well as ignition being out are possible culprits. When it comes to temp 95C in the head is quite reasonable. With antifreeze / corrosion inhibitor the boiling temp is lifted above 100C. But either way a throrough reverse flushing of the cooling system is a good idea. Also check that the radiator is not full of debris blocking the airflow.
All of the above sorted, if the temp is OK at idle but climbs during high speed runs you most likely have a water flow problem. If OK temp at high speed but hot at dawdling you most likely have a fan problem. BTW, have you checked that the fan runs the right way? If the wires have been swapped it runs the wrong way.
