The Met Office has issued a snow and ice warning for a large part of Wales. A band of rain is likely to turn to snow overnight on Monday meaning the Tuesday morning commute could be difficult.
The yellow alert is in place from 9pm on Monday until 10am on Tuesday.
It says: "A band of rain will edge southwards through the course of Monday evening and early Tuesday, this rain turning to snow on hills and perhaps to lower levels in places.
"Many areas will see little or no accumulations of snow, but 1 to 2 cm could settle in some spots, most likely over high ground and southern parts of the warning area. The rain and snow is then expected to turn light and patchy as it slowly clears southern England on Tuesday. As skies clear overnight, ice is also likely to form readily on untreated surfaces."
There has been speculation for days that Arctic winds could bring snow to large parts of the UK.
The areas covered by the warning in Wales are:
- Blaenau Gwent
- Bridgend
- Caerphilly
- Cardiff
- Carmarthenshire
- Ceredigion
- Merthyr Tydfil
- Monmouthshire
- Neath Port Talbot
- Newport
- Pembrokeshire
- Powys
- Rhondda Cynon Taf
- Swansea
- Torfaen
- Vale of Glamorgan.
The northerly airflow will sweep across the UK at the start of this and the Met Office says the introduction of an arctic maritime airmass will bring snow showers from Monday.
Deputy Chief Meteorologist, Chris Almond, said: “Very cold air will spread across the UK from late on Sunday through early next week. This brings with it snow even to low levels in the north and east through Monday and Tuesday, and in excess of 10cm could accumulate, most likely on high ground in the north, but also settling for a time at lower levels.
“With freezing overnight temperatures and the risk of ice, there’s a risk of some travel disruption and wintry hazards are likely to persist through much of next week, even further south for a time, so keep an eye on the Met Office forecast for the latest information.”
BBC Breakfast forecaster Carol Kirkwood said there could be up to 20cm in higher lands in Scotland overnight, with snow falling in lower areas of the UK too.
She said: "As the cold front sinks south it is allowing Arctic air to flow south behind it so a lot of wintry showers will move in. There will be a widespread frost tonight and in areas exposed to the northerly wind will see snow showers with temperatures to -8C in the Highlands.
"Tuesday is going to be a day for wrapping up warm. It will be 5C in Cardiff, but when you add on the wind chill it will feel sub zero for many parts of the country. Tuesday night is going to feel even colder than Monday night with a widespread frost and risk of ice."