There is a major change in the tax law for 2018, which might make it prudent to prepay your property tax before 12-31-17.
If you normally take the itemized deduction on your taxes, those amounts change drastically beginning in 2018. So, if your itemized deductions are normally under $25,000, you may benefit from paying your property tax and donations before the end of 2017 to classify those expenses on your 2017 tax return.