Climatological Winter ended on February 28. Although most people use the astronomical seasons with Winter starting around December 21 on the Winter Solstice and ending on the Spring Equinox. The problem with this is that the exact starting date for the Solstice and the Equinox varies by several days from year to year.
Meteorologists and Climatologists instead use calendar months for the seasons with December 1 though the end of February defining Winter.
Therefore, as of March 1, 2011, the Climatological Winter of 2010-11 has ended.
The attached map shows the departure from normal for the Winter 2010-11 temperatures for the conterminous 48 states. The areas in green and blue experienced a colder than normal Winter and the areas in yellow and orange experienced a warmer than normal Winter. It was a "tale of two winters" with the high Plains and the area to the east of the Missouri-Mississippi Rivers experiencing a colder than normal Winter. The exception to this was the state of Maine which had a warmer than normal Winter.