Met Éireann has issued a status yellow rainfall warning for Cavan and 1o other counties.
The warning also covers Dublin, Kildare, Laois, Longford, Louth, Wicklow, Offaly, Westmeath, Meath and Monaghan.
The Met office issued the warning which came into effect at 7am and will be in place until 6am tomorrow.
The county is to experience heavy rain with between 30 to 35mm expected, as the forecaster predicts showery weather developing over west Connacht and much of Munster.
The days temperatures will be at highs of 16 degrees and some showers may turn heavy and thundery.
Rain overnight will be prolonged and possibly heavy but some dry spells too. Lowest temperatures will be in around the 6 or 8C mark in mainly light or moderate north to northwest breezes.
Tomorrow the rain will slowly ease, continuing patchy in nature through the day. A few showers later which may be heavy, with a slight risk of thunder. Top temperatures 11 to 12 C., in moderate northwest breezes.