The National Weather Service in Caribou has stopped issuing frost advisories and freeze warnings for Northern Maine as of September 20th. This includes all of Aroostook County. It also includes parts of Penobscot County and Piscataquis County north of a line running from near Medway towards Dover-Foxcroft.
Frost advisories and freeze warnings will continue for the Down East region through October 4th or until a freeze occurs. This encompasses Washington County, Hancock County, the southern portion of Piscataquis County, and the southern portion of Penobscot County to include the Bangor area.
The frost and freeze program resumes for the entire forecast area in May 2012.