Little summary follows each chart describing what your looking for.
The ideal paranormal environment where most activity has occurred are on a full and new moon phase. Better your chances by going on those nights.
The best times for ghost investigations are during high geomagnetic fields and solar flares.
In lamest terms, high fields and flares produce more energy which allows spirits to use to manifest or interact.
I provided links to radar and other weather information that may help in your investigation. All up to date info.