Air Properties: Viscosity, Density, k, cₚ & Pr (Dry Air, 1 atm)

Engineering-grade air property table: dynamic & kinematic viscosity, density, thermal conductivity, specific heat (cₚ), and Prandtl number for dry air at 1 atm across −50 °C to 100 °C.

Air Properties vs Temperature (Dry Air, 1 atm)

Property Data

Air properties (dry air at 1 atm) vs temperature. Values are engineering approximations — verify against NIST/REFPROP for critical calculations.
Temperature (°C)	T (K)	Density (kg/m³)	Dynamic Viscosity μ (mPa·s)	Kinematic Viscosity ν (mm²/s)	Thermal Conductivity k (W/m·K)	Specific Heat cₚ (kJ/kg·°C)	Prandtl Number (Pr)
-50	223.15	1.423	0.0135	9.489	0.0205	0.98	0.71
-40	233.15	1.362	0.0142	10.429	0.0212	0.99	0.71
-30	243.15	1.305	0.015	11.494	0.022	0.995	0.71
-20	253.15	1.252	0.0159	12.711	0.0227	0.998	0.71
-10	263.15	1.202	0.0166	13.81	0.0233	1	0.71
0	273.15	1.155	0.0172	14.894	0.024	1.002	0.71
10	283.15	1.112	0.0177	15.921	0.0246	1.003	0.71
20	293.15	1.072	0.0181	16.886	0.0253	1.005	0.71
25	298.15	1.057	0.0183	17.323	0.0256	1.005	0.71
30	303.15	1.042	0.0186	17.848	0.0259	1.006	0.71
40	313.15	1.013	0.0191	18.863	0.0265	1.008	0.71
50	323.15	0.986	0.0196	19.878	0.0271	1.01	0.72
60	333.15	0.96	0.02	20.833	0.0276	1.012	0.72
70	343.15	0.935	0.0204	21.828	0.0281	1.013	0.72
80	353.15	0.911	0.0208	22.832	0.0286	1.014	0.72
90	363.15	0.888	0.0212	23.873	0.029	1.015	0.72
100	373.15	0.946	0.0216	22.841	0.0295	1.017	0.72

Key Insights

•Dynamic viscosity rises slowly with temperature (Sutherland behaviour).
•Kinematic viscosity increases strongly due to falling density (important for Reynolds number).
•Prandtl number for air ≈ 0.71–0.72 across this range (useful for heat transfer correlations).
•Use NIST/REFPROP for very high-accuracy modelling; these values are engineering approximations.

Associated Images

Air Properties: Viscosity, Density, k, cₚ & Pr (Dry Air, 1 atm)

Downloadable Files

air_properties_table.csv