The Met Office has issued a Yellow Status weather warning of heavy rain for Northern Ireland.
The warning applies to every county except County Fermanagh and is valid between 2:00pm on Tuesday and 8:00am on Wednesday.
"Heavy rain leading to some surface water flooding and possible transport disruption later Tuesday and overnight into Wednesday," reads the warning on the Met Office website.
The Met Office also told people what to expect.
"Flooding of a few homes and businesses is likely; bus and train services probably affected with journey times taking longer and spray and flooding on roads probably making journey times longer," added the Met Office.