Britannica Sources used in this answer

When did the Last Glacial Maximum occur?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Map showing the extent of the Laurentide, Cordilleran, and Greenland ice sheets during the Wisconsin glaciation, roughly 100,000 to 11,000 years ago. The Laurentide Ice Sheet covers most of present-day Canada and parts of the northern United States in light blue, the Cordilleran Ice Sheet covers the Pacific Northwest in teal, and the Greenland Ice Sheet is marked in purple. Modern international and state or provincial boundaries are outlined for reference. — Pleistocene Epoch Ice sheets during the Wisconsin glacial episode penetrated deep into North America.

The Last Glacial Maximum (LGM) occurred during the final stage of the Pleistocene Epoch, spanning from approximately 29,000 to 19,000 years ago.12

This interval marked the peak of the most recent glacial period, during which ice sheets and glaciers covered roughly 8 percent of the Earth's surface. The period concluded about 19,000 years ago, initiating a warming trend that caused ice to retreat and sea levels to rise.12