Hundreds of small lakes became filled with Eemian deposits following the retreat of Saalian ice in northwestern Germany. Weakly expressed climate oscillations have been inferred from some local pollen records of Late Saalian sediments. Sea level stood 7 m below the current northwest German sea-level datum (NN) during the interglacial climate optimum and decreased afterward. A uniform vegetational succession of the Eemian mixed forests, correlated with marine isotope stage (MIS) 5e, terminated with the demise of boreal woodlands marked by a steep increase in nonarboreal pollen. This is the onset of the early Weichselian Herning Stade, correlated with MIS 5d. No sharp climate oscillations during the Eemian have been documented. In the ending phase of the interglaciation, the climate deteriorated gradually. Dominant heath and grass tundras point to a substantial decline of summer temperature during the Herning Stade. Sea level then stood at −40 m NN. Sedimentological considerations, supported by counts of partly varved deposits, indicate that the Eemian lasted about 10,000–11,000 yr and the Herning for several millennia.