Road users in the city and county are being advised to use extreme caution while an orange rain warning is in place.
River levels are being monitored and localised flooding is expected, with the worst of the weather forecast for overnight.
Severe Weather Assessment Teams from the city and county are monitoring the weather and pumps have been deployed to known problem locations.
Speaking to RedFM News David Joyce says crews from the City Council are on standby until tomorrow:
"We're not expecting widespread flooding, if anything is going to happen it will be localised in nature and it will be restricted to a local issue in relation to a blocked drain or gully."
Union Quay/South Terrace at high tide this morning.
Businesses on low lying quays have expressed concern about the combination of heavy rainfall and the impact it could have on their premises.
Speaking to RedFM News, Eileen Domiati of Dulce Bun House on Oliver Plunkett Street says businesses always have to be prepared for flooding:
"Well especially with an orange warning, we have to take it seriously, and for us that will mean putting up our flood gates tonight, hoping that the water won't coming up to Oliver Plunkett Street but you actually ever know."
