WASHINGTON (AP) _ Hillary Rodham Clinton pronounced the Christmas season open today as she received the White House's 18 1/2-foot balsam fir.

An improbably warm, summerlike sun greeted the tree at the end of its journey from Endeavor, Wis., as it rolled up the White House driveway on a horse-drawn carriage. ``When you think about this weather, it's a little hard to get into the Christmas spirit. Except that I think it'll start building here at the White House,'' Mrs. Clinton said as temperatures topped 60 degrees.

The first lady was joined outside the South Portico by James and Diane Chapman, who grew the winning tree at their Silent Night Evergreens Farm in Endeavor. The official White House Christmas tree will be set up in the Blue Oval room.

The White House will be shuttered this weekend, Mrs. Clinton said, as teams of volunteers ``with a Santa's-workshop feeling'' scurry to finish the mansion's elaborate holiday decorations by midnight Saturday.

It will take much longer for the Clinton family to dress the tree, which the Chapmans also donated, in the Yellow Oval Room of their personal living quarters.

``It takes us a long time, because we have to take out every ornament and say, 'Awwww, remember this ornament?' And, 'No, don't put it there; put it somewhere else.'

``We decorate over three to four days. It's one of the things we do together as a family. Then, as friends and family come in they all get to kibitz and add to it,'' Mrs. Clinton said.