16 US fluid ounces of water weigh 1.04 pounds at room temperature. While it is common knowledge that 16 ounces equals 1 pint and that “a pint’s a pound the whole globe round,” the weight of the pint is not necessarily exactly 1 pound.
The temperature of the water affects the density and specific gravity of the liquid. Since water has a specific weight of 8.34 pounds per gallon at 32 degrees Fahrenheit, when it is cold enough to cause it to freeze, 16 ounces of water weigh 1.05 pounds.
The weight of 16 ounces is one pound once the water hits its boiling point of 212 degrees Fahrenheit, when its specific weight decreases to 8 pounds per gallon.