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NRW has no flood warnings or alerts in force in Wales. Last successful check: 2026-09-20 06:48:01 UTC.
No current NRW warning or alert matched the location of Merthyr Tydfil No1 River Station. That does not establish warning coverage for the whole town: only these gauge points were checked.
Read Wales’s warnings · Check your area on Natural Resources Wales
Messages: Natural Resources Wales flood warnings API. Warning-area boundaries: Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved. Reused under the Open Government Licence v3.0. Boundaries from DataMapWales.
No official flood warning is active nearby and the closest river stations are within normal ranges.
Updated 2026-09-20 06:50:21 UTC · Official GOV.UK warnings · Flood preparation & help guide
Merthyr Tydfil is the main town in Merthyr Tydfil County Borough, Wales, administered by Merthyr Tydfil County Borough Council. It is about 23 miles (37 km) north of Cardiff. Often called just Merthyr, it is said to be named after Tydfil, daughter of King Brychan of Brycheiniog, who according to legend was slain at Merthyr by pagans about 480 CE. Merthyr generally means "martyr" in modern Welsh, but here closer to the Latin martyrium: a place of worship built over a martyr's relics. Similar place names in south Wales are Merthyr Cynog, Merthyr Dyfan and Merthyr Mawr.
Flood Zones, Warning Areas and Surface Water are Environment Agency maps and cover England only. Merthyr is in Wales, so they draw little or nothing here — that is where the map ends, not an absence of flood risk. Natural Resources Wales’s warning areas have their own pages under flood areas.
Merthyr is monitored by 1 Environment Agency river level station on the Taff, in Merthyr Tydfil. Water levels are updated every 15 minutes, providing real-time flood monitoring for the area.
The Taff is monitored by 1 station (Merthyr Tydfil No1 River Station). Each station records water levels continuously, with data synced to FloodRadar every 5 minutes.
No Environment Agency flood warning area is mapped within 10km of Merthyr. That means the EA has not defined a warning target area here, which is not evidence the town cannot flood: warning areas exist where the EA runs a warning service, and surface-water and groundwater flooding have no warning areas at all. The EA’s register covers England only — Merthyr is in Wales, where the warning service is Natural Resources Wales’s, and FloodRadar publishes its areas alongside the EA’s on the flood areas index.
If flooding is forecast in Merthyr, call Floodline on 0345 988 1188 for the latest information. Move valuables upstairs, turn off gas and electricity if safe to do so, and avoid walking or driving through flood water. Sign up for flood warnings on any station page above to receive email alerts when water levels rise. For emergency numbers, a preparation checklist and insurance guidance, see our flood help & preparation guide.
Merthyr gets about 1,684 mm of rain a year on average (wettest month December, 210 mm; driest June, 93 mm). That is 45% wetter than the UK as a whole, which averages 1,163 mm a year. See the rain gauges →
A thirty-year average for the area, not a forecast and not a flood risk on its own. Source: Met Office HadUK-Grid 1991–2020 (5 km grid), 1.9 km away. Average rainfall: HadUK-Grid v1.3.2, Met Office. Contains public sector information licensed under the Open Government Licence v3.0.
No recorded flood outline within ~5 km of the Merthyr town centre means no flood was mapped here, which is not evidence none happened: the Environment Agency mapped only some floods, mapping effort rose sharply after about 2000, and surface-water flooding is largely absent from this record. The Environment Agency's Recorded Flood Outlines cover England only, and Merthyr is in Wales — so an empty record here is an absence of coverage, not an absence of floods. Open the recorded-floods map →
Current verdict: Normal. No official flood warning is active nearby and the closest river stations are within normal ranges.
Merthyr has river level monitoring on Taff — 1 monitoring station in total.
Use the GOV.UK Check for Flooding service (check-for-flooding.service.gov.uk) or call Floodline on 0345 988 1188 (24 hours). You can also set up free FloodRadar email or browser alerts from any station page above.
Follow official advice: move valuables and vehicles to safety, never walk or drive through flood water, turn off gas and electricity if safe, and check on vulnerable neighbours. See our flood preparation guide at floodradar.co.uk/flood-help.
No recorded flood outline is mapped around the Merthyr town centre means no flood was mapped here, which is not evidence none happened: the Environment Agency mapped only some floods, mapping effort rose sharply after about 2000, and surface-water flooding is largely absent from this record. The Environment Agency's Recorded Flood Outlines cover England only, and Merthyr is in Wales — so an empty record here is an absence of coverage, not an absence of floods. See the flood history link below.
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