Grab a bottle, and look at the mixing chart on the back for the proper water/coolant ratio for your climate's temp range.
Keep in mind, straight water has better thermal transfer properties than straight coolant. The coolant lowers the freezing point, raises the boiling point, lubes the water pump and keeps corrosion at bay.
For NJ, with 0-100 temps seen throughout the year, 50/50 is the only way to go.
Regardless, if you're cooling system is up to snuff, you shouldn't have a problem.