The weather is expected to remain dry for the next few days with daytime temperatures around average for the time of year at 11C or 12C.
Friday is currently forecast to be colder at 10C but remain dry, with the rain arriving on Saturday, along with a slight rise in temperature to 13C.
A spokeswoman at the Met Office said: "There's a front bringing some rain and there is a front with warm air coming in from the south, but at the moment there is come uncertainty about exactly where that will sit and how far north that warm air will push."
She said the timing of the rain and how heavy it will be was also uncertain, but the forecast was for a more unsettled period at the end of the week and also stronger winds.
"It's worth keeping an eye on the forecast, especially if you've got plans, because it could change. That rain may be more overnight or it may push through a day earlier or a day later."