If your 2018 property taxes are assessed, then paying those before 12/31 will let you deduct that amount when filing taxes in 2017. If you wait until next year, then you may not be able to deduct it as your standard deduction is going to be way higher by then. For example, if you owe 5,000 thousand dollars in property tax 2018, then you could save $1,250 by paying it now, assuming that you are in 25% tax bracket.
If your property taxes are not assessed for 2018, then you can’t deduct it in 2017 even if you pay before 12/31/17. So check with your county and find out if your property taxes are assessed for next year. Do it now as we have only a few days left.
The standard deduction for married filing jointly is 24,000 in 2018. So your total deductibles should be more than 24,000 to get any money back which is unlikely if you don’t have a huge mortgage and a massive property tax.
Also, most county websites allow you to see your taxes and pay them online.
Here is my county website.