In the forecast for Saturday, May 11, the Met Office say that further showers will break out throughout the day, with a risk of hail and thunder towards the afternoon - and temperatures reaching no higher than 14C.
However the forecast is expected to pick up for Sunday, May 12, with spells of sunshine and expected highs of 17C.
The forecast said: "Sunny spells will develop during the day with further showers breaking out. Some of these will be heavy this afternoon with a risk of hail and thunder. Light winds. Maximum temperature 14C.
"The showers will die away through the evening with clear spells developing overnight. Quickly becoming chilly with a widespread frost in rural areas and isolated mist or fog patches. Minimum temperature -1C.
"On Sunday it will be a cold start, with any mist or fog quickly clearing. Mostly dry through the day with spells of sunshine. Clear periods overnight with a frost in places. Maximum temperature 17C.
"Chilly start on Monday, then dry with periods of hazy sunshine. Dry on Tuesday and Wednesday with long sunny periods. Becoming warmer by day, but still chilly at night."