Met Éireann has issued a status yellow warning for thunderstorms in Galway which came into effect this afternoon.
The weather forecasters say localised thunderstorms and lightning activity with heavy downpours are possible throughout Friday afternoon.
The warning will remain in place until 10pm tonight, and it affects Cavan, Dublin, Leitrim, Longford, Louth, Meath, Monaghan, Offaly, Roscommon, and Westmeath, as well as Galway.
Tomorrow morning will see any fog or mist clearing away, with sunny spells and scattered showers developing during the afternoon.
Some of the showers may be heavy and thundery again, with spot flooding possible.
Highest temperatures of 16 to 18 degrees are forecast, in light to moderate southerly winds.