Flash floods have caused havoc for motorists nationwide while heavy rains have left shop owners in Cork with a costly clean-up for the second time in eight months.
Some of the worst-hit areas were the M11 north of Bray, the M1 south of Balbriggan, roads in Enniskerry and the Woodenbridge/Aughrim Road in Co Wicklow.
Elsewhere, there were reports of flooding on back roads around Slane, Co Meath, while gardai warned motorists to exercise extreme care on all routes around Letterkenny, Ballybofey and Glenties following snowfall.
More than 15 shops, businesses and houses in the Blackpool area of Cork city were the first and worst hit by flash floods on Thursday night. It is understood many of the property owners do not have flood insurance and are dealing with the second incident in the last year.
A blocked culvert has been blamed for causing the flood with about four feet of water swamping many buildings. Cork City Council has said that the culvert drain had been check twice earlier in the evening and was cleared of debris.
AA Roadwatch issued warnings for routes in several counties with parts of the M11 around Bray closed for hours.
Only one lane of the southbound side of the Dublin to Wexford Road was in use at junction six at Bray/Fassaroe while the northbound side near junction five was also hit by floods. Traffic was also disrupted in Waterford city and other parts of Wicklow, and junction five on the M1 at Balbriggan was impassable.
Dart services were suspended between Howth Station and Howth Junction due to flooding on the line, while Irish Ferries Jonathan Swift fast craft sailings were cancelled.
The Department of Transport urged road users to heed advice from gardai and local authorities after two of the country's busiest roads, the M50 and M11, saw some of the worst localised rain and floods.
Meanwhile, four fishermen on a French-registered trawler were rescued after their vessel got into difficulty on the Irish Sea in the early hours of Friday morning. The 120-tonne Bara An Aod suffered engine failure 2.5 miles east of Wicklow Head and raised the alarm at about 3.15am.