Conversation so far:
What happpened at the valley and apomattox with George Armstrong Custer?
George Armstrong Custer led his Wolverines to Shenandoah Valley where by the year's end they defeated the army of Confederate Lieutenant General Jubal Early in the Valley Campaigns of 1864.
How did Sheridan and Custer defeat the army of Confederate Lieutenant General Jubal?
Philip Sheridan and George Armstrong Custer took part in cavalry actions supporting the Overland Campaign, including the Battle of the Wilderness, and the Battle of Yellow Tavern.
When did the Battle of the Wilderness, and the Battle of Yellow Tavern with George Armstrong Custer take place?
the Battle of the Wilderness, and the Battle of Yellow Tavern with George Armstrong Custer took place during May and June of 1864

Question: Was it in the winter?
Self-contained rewrite: Was it in the winter when the Battle of the Wilderness, and the Battle of Yellow Tavern with George Armstrong Custer took place?