How much colder was global temperature during the Last Glacial Maximum than during the mid-20th century?

During the Last Glacial Maximum (LGM), which culminated approximately 21,000 years ago, the global annual mean temperature is estimated to have been about 4–5 °C (7–9 °F) colder than it was during the mid-20th century.1

It is important to note that this figure represents a global average, and the degree of cooling varied significantly by region. For instance, cooling was much more pronounced at higher latitudes near the poles, while tropical regions near the Equator experienced relatively less cooling. In unglaciated areas, surface temperatures were approximately 5–6 °C (9–10.8 °F) colder than modern averages. These variations highlight the complexity of Earth's climate history, which has fluctuated across diverse timescales throughout the Holocene Epoch and the preceding Pleistocene Epoch.12