2011 Halloween nor'easter

The 2011 Halloween nor'easter, sometimes referred to as "Snowtober," "Shocktober," "Storm Alfred," and "Oktoberblast," was a large low pressure area that produced unusually early snowfall across the northeastern United States and the Canadian Maritimes. It formed early on October 29 along a cold front to the southeast of the Carolinas. As it moved up the East Coast, its associated snowfall broke records in at least 20 cities for total accumulations, resulting in a rare "white Halloween" two days later.

The storm arrived just two months after Hurricane Irene caused extensive power outages and property damage in the Northeast; with the 2011 New England tornado outbreak also causing damage in Western Massachusetts. It dumped snow on trees that were often still in leaf, adding extra weight, with the ground in some areas still soft from a preceding warm, rainy period that increased the possibility trees could be uprooted. Trees and branches that collapsed caused considerable damage, particularly to power lines, with estimates of storm costs ranging between $1 billion and $3 billion. In all, 3.2 million U.S. residences and businesses in 12 states experienced power outages, with the storm also impacting three Canadian provinces.

Some customers in Connecticut did not get power back until early November; many outages lasted 11 days. Many communities chose to postpone celebrations of Halloween from two days to a week later as a result, or cancel them entirely. Delays in restoring power led to the resignation of the chief operating officer of Connecticut Light & Power amid widespread criticism of the company's mishandling of both the nor'easter and Irene.