Drivers in Essex were urged not to travel unless the journey was essential after heavy snow hit the south and west of the county.
Collisions were reported on major routes, including the A13 in Corringham, the A12, the M11 and M25.
Gatwick Airport shut its runway for part of the day, and British Airways cancelled all flights out of Heathrow until conditions improved.
Overnight, temperatures reached -17.2C in parts of Norfolk.
Some weekend sporting fixtures were also cancelled as temperatures plunged.