The weather on Thursday will be mainly fine, the Met office said.
Temperatures will be 15 C inland, 17 C on the coasts and 4 C in the mountains, where there will be ice.
Tonight, temperatures will drop to 3 C inland, 7 C on the coasts and 3 C in the mountains.
On Saturday the weather will be cloudy at intervals. Rain and sleet in the mountains are expected after noon.
Temperatures will edge up to the average for the time of year.
On Sunday, the weather will be cloudy at intervals with isolated rain. Snow and/or sleet is expected in the mountains.