Natural Resources Wales warned communities to prepare for heightened flooding risk over autumn, citing long-range forecasts predicting wetter and windier conditions than usual over the coming months.
The organisation said one in seven properties in Wales faces flood risk, but only 27% of those eligible for phone or email flood warnings are currently signed up. NRW's Jeremy Parr said people need to "think the unthinkable" about what they would do if flooding struck their area, noting that residents who had experienced major floods often told the organisation they had never flooded before and did not expect it to happen.
Wales faces particular vulnerability due to its geography. The country has a vast coastline and several fast-responding rivers that can fill rapidly as rain runs off steep terrain in south Wales valleys. Surface water flooding, where local drainage systems become overwhelmed during heavy rainfall, poses an increasing danger. More than 274,500 homes and businesses are currently classified at risk of flooding, with that figure expected to increase significantly by century's end.
The warning comes after recent major flooding events. Storm Claudia hit Monmouth in November 2025, causing severe damage that residents said was unlike anything they had experienced in their lifetimes. Four of Monmouth's long-time residents, aged 81 to 82, described harrowing scenes when the flood struck at 2:30 in the morning. One said eighteen cars on his road were lost, including his own, and houses behind his flooded completely. He noted the town has three rivers running into it and winters are changing.
Sarah Davies from the Met Office said long-range forecasts for October, November and December suggested a greater chance of weather-related disruption. Jeremy Parr acknowledged that while NRW invests in flood defences, "you can't stop all of the flooding all of the time."
The organisation's flood warning service covers 181,158 properties in Wales. NRW advises people to check their flood risk by postcode online, sign up for warnings, and access guidance on what to do if flooding is forecast. Parr suggested people may avoid signing up due to myths that it could affect insurance premiums.