The UK has recorded its chilliest January night in 15 years, as forecasters predicted it could get even colder over the weekend with temperatures falling as low as -20C in some locations.
Altnaharra, in Sutherland, the most northerly region of the Highlands, reached the low of -17.3C by 9pm on Friday. It is the coldest January overnight temperature since 2010, when it dropped below -15C several times at locations across the UK, including -22.3C on 8 January in Altnaharra.