Apart from the nasty weather, the very next day is booked by the God Lot for their own festivities, so the forces of evil have to knock off their shenanigans at midnight.
At least the God Lot have their nice long robes and warm (solar-powered?) haloes:
The witches tend to be quite inadequately dressed for the season:
drawing of a witch by Guercino 1591 - 1666
Perhaps the witches etc a hardy lot, but whether they're as impervious to cold as polar bears wearing thermal underwear and ear muffs, they should have had the sense to schedule the day away from the God Lot's beano.
I mean, Hallowe'en. The clue's in the name, isn't it!
Word To Use Today: Hallowe'en. The e'en bit is short for evening, and to hallow something means to set it apart because it's sacred. The word comes from the Old English hālig, which means holy.