Halloween got off to a scary subfreezing start for the whole Philadelphia area, from Doyletown to Downingtown to Atlantic City. Ice was responsible for a variety of accidents, according to traffic.com (http://go.philly.com/traffic).
Fog was also a problem to north and west, from Lancaster to Allentown.
Tick-or-treaters should see dry skies and temperatures rising into the mid 50s this afternoon, according to the National Weather Service.
Temperatures will get a bit warmer for the rest of the week, with highs in the upper 50s and lows mostly in the 40s, especially for a possible dip into the upper 30s Wednesday night. Normal for late October, early November are highs in the low 60s, lows in the mid 40s.