Viscosity is first and foremost a function of material. The viscosity of water at 20°C is 1.002 centipoise. Most ordinary liquids have viscosities on the order of 1 to 1000 centipoise. Pastes, gels, emulsions, and other complex liquids are harder to summarize. Some fats like butter or margarine are so viscous that they seem more like soft solids than like flowing liquids. From everyday experience, it should be common knowledge that viscosity varies with temperature.