Until the point where the superconductor undergoes decomposition, it can have any temperature. However, it is important to note that the superconducting material will only display superconductivity at a temperature below its critical temperature. Many metallic elements have the ability to display superconductivity (but they only superconduct at extremely low temperatures). For example, lead (Pb) becomes a superconductor when cooled to temperatures below 4 Kelvin.
Conventional superconductors typically have critical temperatures ranging up to 25 Kelvin. The relatively high-temperature cuprate superconductors are known to exhibit superconductivity at temperatures above 77 Kelvin (which is the temperature of liquid nitrogen). Typically, the temperature at which a superconductor exhibits superconductivity is below 10 Kelvin. The superconducting temperature varies from material to material (since different elements/alloys exhibit superconductivity at different temperatures). Hydrogen sulphide (chemical formula: H2S), when put under over 150 gigapascals of pressure, is a high-temperature superconductor whose transition temperature is approximately 80 Kelvin.