Today, Monday, is a reasonably dry and bright day, but things are soon set to take a turn for the worse.
Temperatures will plunge this evening, leading to a bitterly cold night, with the possibility of sleet and snow in places.
Widespread frost formation is expected by Tuesday morning as temperatures remain at 0-4C. Tuesday itself is expected to be a largely dry day, with some wintry showers possible in the northwest.
Cold conditions are forecast to remain until Friday, with daytime temperatures hovering around the 5-8C.
Milder and more changeable weather is expected from Friday onwards.