Lithium has a boiling point of 1,342 degrees Celsius and a freezing point of 180.5 degrees Celsius. Due to lithium's high freezing point, it exists as a solid at room temperature.
The freezing point of lithium is the same as its melting point. It is where the solid and liquid phases of lithium exist in equilibrium. While lithium's melting point is very low compared with many of the transition metals, it is the highest of any of the alkali metals. For comparison, sodium has a melting point of 97.7 degrees Celsius, while hydrogen has a melting point of negative 259.1 degrees Celsius, which is close to absolute zero.