Parts of the UK are bracing for snow and wintry showers this week as the cold spell continues.
Temperatures dropped below freezing for much of the country over the weekend, with lows of -8C (17.6F) forecast for Tuesday.
The coldest recorded temperature so far this autumn was -7.7C in Shap, Cumbria, on Saturday morning.
OceanNewsUK Weather says snowfalls are possible but there is "a lot more uncertainty than normal" in forecasts.
Tuesday night will bring frost to much of the country, with temperatures of around -2C to -5C, and possibly as low as -8C, across parts of the north of England and rural Scotland, the Met Office said.
Higher ground in Scotland and northern England saw snowfall last week, which is typical for late November.
There is now potential for snow further south from Thursday as temperatures drop.
The cloudy and damp start to the week will give way to sunnier spells, before turning unsettled on Thursday and Friday, forecasters say.
Lead OceanNewsUK Weather presenter and meterologist Simon King said: "It's going to be a cold week with temperatures only around 2 to 7 degrees Celsius - which is below the average for the time of year."
While there's the potential for snow later in the week, Mr King adds: "Here's the big caveat. There's a lot more uncertainty than normal in the forecast and therefore this prospect of snow.
"One weather model we use, the American 'GFS', is showing an area of rain, sleet and snow - even to low levels - moving in across southern parts of the UK. Snow showers also across northern and eastern areas.
"Another weather model, the European 'EC', is different and doesn't have this snow signal for southern parts but instead is showing wintry showers for some.
"Forecasting snow in the UK in December is actually really tricky. Being an island, it's typically not quite cold enough and we still have a battle between milder tropical air and colder Arctic air.
"Weather forecast models need to start agreeing on certain aspects before we can be more confident on the forecast later this week. Stay tuned."
Parts of central Scotland woke up to frost on Monday morning following cold overnight temperatures falling to -6.4C in the village of Tyndrum, according to the Met Office.
It stayed above freezing for the rest of the country as bands of cloud and rain moved in.
The rain will be heavy at times across Wales and south-west England throughout Monday, before an area of low pressure pulls south-eastwards towards Continental Europe to create brighter spells.
Showers and hill snow could still affect parts of Scotland and north-east England, where it will also be windy.
The low temperatures will persist through Tuesday and Wednesday, with sunny spells forecast.
An area of low pressure moving in from the South West on Thursday could meet colder air, with showers expected across southern England and Wales, turning to snow over higher ground.
The temperature will peak in double figures in southern England and Wales on Monday, before dropping again into Tuesday.
