Six people were rescued overnight following flooding in the north-west.
Donegal County Council says heavy rain caused damage to roads and bridges in East Inishowen, with significant debris on the main Muff to Moville Road.
The Northern Ireland Fire and Rescue Service (NIFRS) say one person was rescued from a vehicle - while five others were taken from flooded properties.
A NIFRS spokesperson says: "Between 7:04pm on July 23rd and 1:30am on July 24th, Northern Ireland Fire & Rescue Service received a total of 106 emergency 999 flood-related calls.
"[This] resulted in our firefighters responding to 49 operational incidents.
"NIFRS rescued one person from a vehicle in water and five persons trapped within flooded properties."
And heavy rain in Derry city also saw severe flooding in the Strand Road, Bogside and Craigavon Bridge areas.
Some admissions to the Emergency Department at Altnagelvin Hospital in Derry were also affected.
Additional reporting: Caoimhseach Connolly