Conductivity is generally affected by temperature in different ways depending on the type of material:

 Conductivity is generally affected by temperature in different ways depending on the type of material:

Solutions

For solutions, conductivity increases with temperature because the mobility of ions increases. This is due to the following factors: 

Ionic mobility: As temperature increases, the mobility of ions in the solution increases. 

Solubility: As temperature increases, the solubility of many salts and minerals increases. 

Number of ions: As temperature increases, the number of ions in the solution may increase due to dissociation of molecules. 

Metals

For metals, conductivity decreases with temperature because the molecular vibrations increase. This increases the mean free path of molecules, which obstructs the flow of free electrons. 

Non-metals

For non-metals, conductivity increases with temperature because there are no free electrons. 

To account for temperature differences, reference values for conductivity are usually reported at a temperature of 298 K (≈ 25 °C or 77 °F). For measurements taken at other temperatures, a "compensated" value can be calculated.