Not just for the end of the year, but I check that I’ve paid enough in taxes. Roth conversions (for US folks), investment income in taxable accounts, retirement distributions, etc can all generate taxable income that pushes tax liability too far above the amount covered by payroll withholding and result in penalties.
Edit: Specified that Roth conversions are for US folks
Nice to see natural gas so much lower than the national average (24% of energy produced vs 43% nationwide).