Friday was the coldest January night in the UK in 15 years after temperatures plummeted to -18.9C in a hamlet in northern Scotland, the Met Office said. Altnaharra, in the Highlands, recorded the temperature on Saturday morning, the Met Office said. It is the coldest January overnight temperature since 2010, when temperatures dropped below -15C several times at locations across the UK, including -22.3C on 8 January in Altnaharra. Forecasters previously said there was a very small probability it could reach -19C. Walkers on Wimbledon Common in south-west London. Photograph: Amer Ghazzal/REX/Shutterstock Much of the UK endured below freezing temperatures