If you're looking at forecasting your next months expenses, take the higher months and use that as a benchmark for your next budget ;-)

What we did was made an excel sheet of all our monthly expenditures over a year, including our utility bills, but not our personal expenditures. That gave us a rough idea of how much we're spending on groceries, dining out, etc. on a monthly basis and on an average.

If need be I can share that sheet with you, lemme know!