A status yellow heavy rainfall warning remains in place across Connacht until 9pm tonight, with a risk of some localised and river flooding.
Up to 50 mm of rain are expected - possibly higher in mountainous areas.
Gardai are advising motorists to slow down, as there's a lot of surface water on roads.
Residents in the Lough Funshinagh area of Co Roscommon have said heavy rain overnight is threatening to flood a number of houses in the area. Roscommon County Council is putting in place measures to try to raise local roads and pump out flood water in the Rahara area.
Met Eireann meanwhile has issued a weather advisory for the entire country for the rest of the week, as conditions are due to take a cold turn again from tomorrow.
The forecaster is warning that it will become "increasingly wintry" with a risk of frost and icy conditions, and there will also be a chance of sleet and snow in parts.