Some schools are closed and many more starting late as sub-zero wind chills and very cold temperatures hit southern New England.
Boston, Providence, Worcester and Springfield are among the larger districts closing Thursday as a precaution.
Connecticut, Rhode Island and Massachusetts have advisories for wind chill conditions equal to 20 below zero until 11 a.m., and parts of western and north central Massachusetts have warnings for wind chills around minus-30.
Early morning lows between 5 and 15 degrees below zero were forecast for the Berkshires and Worcester hills. Elsewhere in Massachusetts, Connecticut and Rhode Island, lows between 5 above to 5 degrees below zero were forecast. Temperatures and winds are expected to moderate later.
A high wind watch for 60 mph gusts is issued from late Thursday into Friday afternoon for south coastal Massachusetts and nearby islands.
Dozens of schools in New Hampshire are starting classes later to cope with the bitter cold - with wind chill temperatures forecast at 30 degrees below zero.
Many schools posted a two-hour delay and some kindergarten and pre-k classes were cancelled altogether.
Mark Joyce, executive director of the New Hampshire School Administrators Association, says the delay gives the sun a chance to climb higher and offers some relief to students who walk to school or bus stops.
Joyce also says that 40 percent of the state's schools were built before 1950 and older heating systems take longer to warm them the colder it is.
Winds of up to 20 mph are expected, with 30 mph gusts. A wind chill advisory is in effect at least through Thursday morning.
Low temperatures with double-digit wind chills have led to some school closings and delays in Vermont.
A wind chill warning was in effect until noon Thursday for the state.