In general, the viscosity of air is only slightly dependent on the pressure but is strongly related to temperature.
The dynamic viscosity directly correlates with the square root of temperature μ ∝ √T, and density is inversely proportional to temperature: ρ ∝ 1/T. Therefore, we can relate these two proportionalities and derive the relationship between kinematic viscosity and temperature as ν = T3/2.
As you can see now, when the temperature rises, the viscosity of the air increases. This distinguishes air and most gases from the viscosity of liquids. For liquids, viscosity generally decreases as temperature increases. Read more