How long did interglacial periods usually last during the Pleistocene?

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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.

During the Pleistocene Epoch, the Earth experienced a series of alternating glacial and interglacial stages. According to oxygen isotope records from ocean sediments, interglacial periods typically lasted between 10,000 and 15,000 years.1

These interglacial stages represent intervals when the Earth's climate was as warm as it is today, occurring between the colder glacial stages when ice sheets were much more extensive. While these cycles were driven by orbital variations, the Earth system has been in constant flux, and most of the past 500,000 years were spent in intermediate glacial states rather than in the extremes of either full glacial or interglacial conditions.21