Freezing cold air moving towards Derry from Siberia will see temperatures here drop to as low as -9°C this week, according to the Met Office.
The air is gradually moving in from Russia right across Europe and Derry is expected to feel its force over the coming days.
The temperature in Derry on Thursday will be below freezing but when the windchill factor is taken into consideration the 'feels-like' temperature will drop to as low as -9°C.
The Met Office issued a yellow status weather warning of snow for some parts of the North. The warning is valid for most of Wednesday and Thursday.
"Heavy snow showers are expected on Wednesday," said the Met Office.
"There is the potential for travel delays on roads, with some stranded vehicles and passengers, as well as delays or cancellations to rail and air travel.
"Some rural communities could become cut off. Power cuts may also occur and other services, such as mobile phones, may be affected."