It seems to many people that trees have dropped their leaves earlier this year and that fall color came sooner than expected.
This may be due to the drought this summer and dry conditions this fall. Trees under drought stress typically develop fall coloration earlier. It is wise, even this late in the year to water "evergreen" trees like White pine, Spruce and arborvitae. This type of plant material - particularly newly installed - will need moisture throughout the winter. Mulching any new plant material can help alleviate dessication in winter.