The average surface temperature of the Earth’s surface is

The average surface temperature of the Earth is approximately 15°C (59°F). This value represents the global mean surface temperature (GMST), which is a combination of near-surface air temperatures over land and sea surface temperatures [1]. While specific regions vary drastically—from equatorial ocean surfaces averaging 27°C to polar regions near 0°C—the integrated global average is traditionally cited as 15°C in geographical and scientific literature [2]. Some modern datasets and climate models have occasionally used 14°C as a baseline for specific 20th-century averages, but 15°C remains the standard textbook value for the planet's overall surface temperature [2]. This temperature is maintained by the Earth's heat budget, where the incoming solar insolation is balanced by outgoing terrestrial radiation, preventing the planet from accumulating or losing net heat [3].

Sources

1. [1] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 12: Water (Oceans) > Horizontal and Vertical Distribution of Temperature > p. 104
2. [2] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 13: Our Home: Earth, a Unique Life Sustaining Planet > Table 13.2: Planets in our solar system > p. 213
3. [3] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 8: Solar Radiation, Heat Balance and Temperature > Heat Budget of the Planet Earth > p. 69