Temperatures in parts of Britain plummeted to below minus 21C overnight, with forecasters predicting no let-up in the cold snap as widespread icy conditions continued to cause disruption Friday. Severe weather warnings remained in place for much of the country with ice and sub-zero temperatures making for treacherous driving conditions and further heavy snow forecast in some areas. “All in all quite a cold night again, everywhere across the UK was below zero,” said Met Office forecaster Charles Powell. “As a result most people are waking up again to widespread ice across the whole country, so it is going to be a major problem for transport.” Temperatures hit a low of minus 21.1 C in northern Scotland overnight, with minus 11 C recorded in Northern Ireland, minus 16.4C near Manchester in England, and minus 14.5 C the low in Wales. Forecasters expect Friday to be mostly dry and bright across Scotland, western England and Wales, although temperatures will remain very cold. Up to 5 cm of snow is predicted across north east England, east Anglia and the east coast. “It looks set to continue certainly for the next week to week and a half,” said Powell. “There is no respite, no significant increase in temperatures.” Thousands of schools across the country remain closed, threatening to impact next week's GCSE and A-level exams in England, Wales and Northern Ireland if they are unable to reopen amid the continuing cold snap.