- Put differently, isotherms are as important as latitudes in determining what constitutes Arctic and Subarctic regions.
- In tropical and subtropical mountains the tree line occurs where the summer isotherms are as low as 3-6°C.
- The average temperature of an underground site reflects the yearly isotherm of the area.
- Humboldt used lines, called isotherms, to delineate regions of equal temperatures.
- The Curie isotherm is a temperature surface in the Earth's subsurface connecting depths at which Curie temperatures are reached.