Dave: Yes, it should. Your life changes every month, and your budget should reflect the ebb and flow of your life.
Now, some things will stay the same. Your house payment or rent should fall into this category. If you have a car payment, which I hope you don’t, that would be the same too. There shouldn’t be a big difference in the amount you spend on food most months though. You might spend more in this category during November and December thanks to the holidays, but overall it should remain pretty steady.
The biggest fluctuation you may see is in your utilities. I heat my house with natural gas, so the bill is much higher during the winter months. It’s just the opposite during the summer. We burn electricity to run the air conditioner, so the electric bill is higher in summer.
This is part of the reason I urge people to do a budget on paper, on purpose, before the next month begins. You may look at the upcoming month and realize the kids have soccer pictures scheduled. There may be a school trip planned, or they may need back-to-school clothes and supplies.
When it comes to a budget, there’s no easy out. Things change from month to month, and you need to think, plan ahead, and itemize so your budget is an accurate reflection of your life!