Northern Ireland is expected to experience some of the worst of a heavy spell of rainfall on Sunday evening into Monday.
Forecasters predict the region could see half a month’s worth of rain in less than a day.
It comes as yellow-level rain warnings were put in place for the eastern counties of Northern Ireland, as well as several counties south of the border.
The Northern Ireland warning applies for Antrim, Armagh and Down between 6pm on Sunday until 6pm on Monday.
The expected rainfall carries a risk of flooding, power cuts and dangerous driving conditions.
Yellow weather warnings for rain and thunderstorms are in place across large parts of the UK today and tomorrow ⚠️
— Met Office (@metoffice) July 20, 2025
A lot of rain falling within a short space of time may lead to localised flooding 🌧️
Check the latest info here 👉 https://t.co/QwDLMfRBfs pic.twitter.com/rz84D5qwyl
Forecasters also warn there is a small chance that some communities could be cut off by flooded roads while fast-flowing or deep floodwater could pose a danger to life.
Simon Partridge, a forecaster with the UK Met Office, said: “It looks like Northern Ireland is the place where we could see the most rainfall and certainly the most impactful rainfall.
“They could see 50 to 75mm of rain within 12 to 18 hours.”
The region records an average of 89mm of rain in July, meaning more than half a month’s rainfall could hit Northern Ireland in less than a day.
A yellow-level thunderstorm warning was in place for the western half of Northern Ireland between midday and 8pm on Sunday.
⚠️Status Yellow Rain warning for Dublin, Kildare, Louth, Meath, Wicklow & Monaghan
— Met Éireann (@MetEireann) July 20, 2025
⏲️Valid: 00:00-12:00 Mon 21/07/2025
➡️Spells of heavy rain with a chance of isolated thunderstorms
Potential Impacts:
• Localised flooding
• Poor visibility
• Difficult travelling conditions pic.twitter.com/dfqTOLHnfo
The Republic of Ireland’s forecasting agency, Met Eireann, issued its own yellow-level warning for Dublin, Kildare, Louth, Meath, Wicklow and Monaghan.
The warning applies from midnight until midday on Monday.
It said there will be spells of heavy rain with a chance of isolated thunderstorms, localised flooding, poor visability and difficult traffic conditions.
It followed earlier thunderstorm warnings for Cork and Clare in the south-west of the country, which had both expired by 7pm.
