Density and Specific Gravity of Water vs. Temperature (SI Units, 1 atm up to 100°C, saturation pressure above)
Temperature(°C)	Pressure(kPa)	Density(g/cm³)	SG (4°C ref)	SG (15°C ref)	SG (15.6°C ref)	SG (20°C ref)
0.1	101.3	0.99985	0.99987	1.00075	1.00083	1.00165
4	101.3	0.999975	1	1.00087	1.00096	1.00177
10	101.3	0.999703	0.99973	1.0006	1.00069	1.0015
15	101.3	0.999103	0.99913	1	1.00009	1.0009
20	101.3	0.998207	0.99823	0.9991	0.99919	1
25	101.3	0.997047	0.99707	0.99794	0.99803	0.99884
30	101.3	0.995649	0.99567	0.99654	0.99663	0.99744
40	101.3	0.99222	0.9922	0.9931	0.9932	0.994
50	101.3	0.98804	0.9881	0.9889	0.989	0.9898
60	101.3	0.9832	0.9832	0.9841	0.9842	0.985
70	101.3	0.97776	0.9778	0.9786	0.9787	0.9795
80	101.3	0.97179	0.9718	0.9727	0.9727	0.9735
90	101.3	0.96531	0.9653	0.9662	0.9663	0.967
100	101.4	0.9584	0.9584	0.9592	0.9593	0.9601
120	198.9	0.9431	0.9431	0.944	0.944	0.9448
140	362.3	0.9261	0.9262	0.927	0.927	0.9278
160	620.1	0.9075	0.9075	0.9083	0.9083	0.9091
200	1553	0.8647	0.8647	0.8654	0.8655	0.8662
250	3976	0.7992	0.7992	0.7999	0.8	0.8006
300	8588	0.7121	0.7122	0.7128	0.7128	0.7134

Source: engineeringtoolbox.com

Properties

Specific Gravity (SG) is a dimensionless ratio of the density of a substance to the density of a reference substance under specified conditions. Its value is the same in both SI and Imperial unit systems.
For liquids and solids, the reference is typically pure water. Common reference temperatures are 4°C (where water density is ~1000 kg/m³), 15°C, 15.6°C (60°F), and 20°C (68°F).
For gases, the reference is air at room temperature (25°C).
The temperature and pressure of both the sample and the reference must be specified when reporting or using Specific Gravity values.
The density of water decreases as temperature increases above 4°C, which causes its specific gravity (relative to a colder reference) to fall below 1.0.

Water Temperature Specific Gravity