Thermal equator
![Sea Surface Temperature Analysis clearly shows highest temperatures (28°C and more) along the 10° North latitude and not along the geographic equator. The reasons are the two cold currents: California Current at Northeast and Humboldt Current along the equatorial line. Hawaiian Islands (in white) have higher temperatures than the equatorial line near the coast of South America because cold waters from upwelling along California Coast are farther away than Thermic Equator and, therefore, these cold waters warm up for several thousands of km.](/Images/godic/202502/16/Ecuador_térmico2320.png")
The thermal equator (also known as "the heat equator") is a belt encircling the Earth, defined by the set of locations having the highest mean annual temperature at each longitude around the globe. Because local temperatures are sensitive to the geography of a region, and mountain ranges and ocean currents ensure that smooth temperature gradients (such as might be found if the Earth were uniform in composition and devoid of surface irregularities) are impossible, the location of the thermal equator is not identical to that of the geographic Equator.