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Pedestrianised section of Bridge Street, WarringtonPhoto: Stephen Craven · CC BY-SA 2.0
C−Hazard risk Grade
Flood & hazards in Warrington · Environment Agency

In Warrington, 3.2% of homes face high or medium risk from rivers or the sea and 4.3% from surface water

On the Environment Agency’s maps, which allow for flood defences, “high or medium” means at least a 1 in 100 chance of flooding from rivers or the sea in any year. Hazard risk puts Warrington at C−.

2021worst recorded flood144flood warnings since 20069%in a radon Affected Area
In brief

What stands out about Warrington’s hazards

From the Environment Agency’s maps and records and the BGS radon atlas, below.

Remembers 2021Floodwater covered 84 hectares of today’s Warrington in 2021; 1,347 of today’s households live inside past flood outlines.The Sankey Brook ran its 2nd-highest in January 20253.16 m at Causey Bridge on 1 January 2025, 4 cm under the record set in 2000.144 flood warnings since 2006For the parts of Warrington the Environment Agency warns directly; the most recent on 8 October 2025.
By hazard

What Warrington faces

Each hazard against its own yardstick; meters run from low to high on that yardstick.

Rivers and the sea

3.2%of homes at high or medium risk
More than the typical UK town · more than 85% of towns
2,540 homes by the EA’s own count

Surface water

4.3%of homes at high or medium risk
More than 60% of UK towns
Rivers and sea: 3.2%

Past floods

12years with a recorded flood
Last recorded: January 2025
1,347 households inside past outlines

The Sankey Brook

2.36 mhighest in winter 2025–26 at Causey Bridge
20th-highest of 35 winters
Record 3.20 m, October 2000

Flood warnings

144flood warnings since 2006
279 flood alerts for the wider area
Last warning 8 October 2025

Radon

9%of the city in a radon Affected Area
Highest band here: 1–3% of homes
No square of 5% or more
Not on this page: coastal erosion, subsidence and shrink-swell ground (the British Geological Survey licenses it), groundwater flooding and reservoir failure.
Hazard risk Grade

Warrington grades C− for hazard risk

Flood risk from rivers and the sea, against all UK towns.

Homes at high or medium flood risk (3.2%)Fewer than 15% of UK towns

The share of homes at high or medium risk from rivers and the sea, ranked against every UK town of 1,000 or more: fewer homes at risk is better. Towns with none at high or medium risk are ordered by their share at low risk, so they don’t all share one score. Surface water and radon aren’t graded: they are described below.

Flood map

Where the water goes in Warrington

Turn layers on and off. Blue is the risk from rivers and the sea; pink is where heavy rain collects. Both allow for flood defences.

Recorded flood: 1978Recorded flood: 1990Recorded flood: 1997Recorded flood: 1999Recorded flood: 2000Recorded flood: 2001Recorded flood: 2002Recorded flood: 2013Recorded flood: 2015Recorded flood: 2021Recorded flood: 2024Recorded flood: 2025© OpenStreetMap contributors · EA NaFRA2
HighMediumLowrivers & seaHighMediumLowsurface waterWarrington’s built-up area

The river and sea risk follows the Glaze Brook, the Sankey Brook and the River Sankey. Surface-water risk is spread across the city, in dips, underpasses and along small streams, which is why more homes are exposed to it.

Rivers and the sea

3.2% of Warrington’s homes are at high or medium risk from rivers or the sea

The Environment Agency’s national map, allowing for defences. A further 11% are at low risk.

High risk1.2%of homes · 1 in 30 a year or more914 homes, EA count
Medium risk2.1%of homes · 1 in 30 to 1 in 1001,626 homes, EA count
Low risk11%of homes · 1 in 100 to 1 in 1,0008,481 homes, EA count
Where Warrington sits among 3,735 UK towns
35%None
23%Under 0.5%
9%0.5–1%
11%1–2%
11%2–5%Warrington
5%5–10%
3%10–20%
2%20% +

Share of each UK town’s homes at high or medium risk from rivers and the sea. 35% of UK towns have none; Warrington has more than 85% of towns.

Towns its size: 38th of 41 from the fewest homes at risk
#TownPeopleHigh or med.
1Islington London216,3090%
2Camden London209,3420%
3Westminster London203,5710%
…
36Blackpool Lancashire149,0872.7%
37Slough Berkshire166,8682.9%
38Warrington Cheshire174,9683.2%
39York North Yorkshire141,6964.3%
40Kingston upon Thames London166,3334.5%
41Oxford Oxfordshire170,7994.7%

UK towns of 122,000 to 245,000 people.

The Environment Agency’s Risk of Flooding from Rivers and Sea (NaFRA2, June 2026) counts each postcode’s homes by band; the shares weight those postcodes by Census 2021 households. The EA counts include homes built since 2021.

Surface water

Heavy rain puts about 1.3 times as many Warrington homes at risk as rivers and the sea do

Surface water is rain that falls faster than drains and the ground can take it. It is mapped separately from rivers and the sea, and it is not in the Hazard risk Grade.

Surface water4.3%
Rivers and the sea3.2%
0%10.5%21% of homes

About 1.6% of homes are at high risk of surface-water flooding (a 1 in 30 chance or more each year) and 2.7% at medium risk: roughly 3,260 households. A further 12% face a low risk from surface water. That is more than 60% of UK towns.

~3,260
households at high or medium risk
12%
of homes at low risk
60%
of UK towns have a smaller share
89,034
addresses read on the map

Our estimate: every address in the city (ONS NSUL) read on the Environment Agency’s Risk of Flooding from Surface Water map (NaFRA2, 2025), each postcode’s share weighted by its Census 2021 households. Neither agency publishes a count of homes for surface water, so treat it as a guide; one street can differ from the next.

Flood history

Warrington has flooded in 12 recorded years since 1978, most of all in 2021

Every flood the Environment Agency has mapped inside Warrington’s built-up area, newest first. The record is fullest for big river floods; small and surface-water floods are often missing.

  1. 2025January 2025: River flooding recorded7 hectares inside today’s built-up area
  2. 2024April 2024: River flooding recordedUnder 1 hectare inside today’s built-up area · Warrington - Bottle Gas
  3. 2021January 2021: River flooding recorded84 hectares inside today’s built-up area · Warrington - Callands, Warrington - Penketh, Warrington - Dallam
  4. 2015December 2015: River flooding recorded1 hectare inside today’s built-up area
  5. 2013December 2013: The sea came in3 hectares inside today’s built-up area
  6. 2002January, February and August 2002: River flooding recordedUnder 1 hectare inside today’s built-up area
Show all 12
  1. 2001April and May 2001: River flooding recorded2 hectares inside today’s built-up area
  2. 2000June, October and November 2000: River flooding recorded20 hectares inside today’s built-up area
  3. 1999December 1999: River flooding recordedUnder 1 hectare inside today’s built-up area
  4. 1997October and December 1997: River flooding recordedUnder 1 hectare inside today’s built-up area
  5. 1990February 1990: The sea came in30 hectares inside today’s built-up area
  6. 1978December 1978: River flooding recorded44 hectares inside today’s built-up area
The worst: 202184 ha

Floodwater covered 84 hectares of what is now Warrington in 2021, the largest flood the record holds here (January).

1,347 of Warrington’s households today live inside the outline of a recorded flood.

Since 2021, the largest recorded flood inside the city covered 7 hectares.

River levels

The Sankey Brook in January 2025 rose to its 2nd-highest level since 1990

The highest level each winter (October to September) at the Environment Agency’s Causey Bridge gauge, since 1990. The river normally runs between 0.21 m and 2.50 m here.

Highest level each winter, metres
Winter 1990–91: highest 2.21 m · 0 days above the normal rangeWinter 1991–92: highest 1.92 m · 0 days above the normal rangeWinter 1992–93: highest 2.39 m · 0 days above the normal rangeWinter 1993–94: highest 1.95 m · 0 days above the normal rangeWinter 1994–95: highest 2.63 m · 1 days above the normal rangeWinter 1995–96: highest 1.21 m · 0 days above the normal rangeWinter 1996–97: highest 1.60 m · 0 days above the normal rangeWinter 1997–98: highest 2.28 m · 0 days above the normal rangeWinter 1998–99: highest 1.92 m · 0 days above the normal rangeWinter 1999–00: highest 2.65 m · 2 days above the normal rangeWinter 2000–01: highest 3.20 m on 30 October 2000 · 2 days above the normal rangeWinter 2001–02: highest 2.75 m · 2 days above the normal rangeWinter 2002–03: highest 2.67 m · 1 days above the normal rangeWinter 2003–04: highest 2.85 m · 2 days above the normal rangeWinter 2004–05: highest 2.77 m · 1 days above the normal rangeWinter 2005–06: highest 2.09 m · 0 days above the normal rangeWinter 2006–07: highest 2.31 m · 0 days above the normal rangeWinter 2007–08: highest 2.91 m on 6 September 2008 · 5 days above the normal rangeWinter 2008–09: highest 2.69 m · 4 days above the normal rangeWinter 2009–10: highest 2.34 m · 0 days above the normal rangeWinter 2010–11: highest 1.93 m · 0 days above the normal rangeWinter 2011–12: highest 2.97 m on 26 September 2012 · 4 days above the normal rangeWinter 2012–13: highest 2.57 m · 2 days above the normal rangeWinter 2013–14: highest 1.49 m · 0 days above the normal rangeWinter 2014–15: highest 1.49 m · 0 days above the normal rangeWinter 2015–16: highest 2.97 m on 26 December 2015 · 1 days above the normal rangeWinter 2016–17: highest 2.17 m · 0 days above the normal rangeWinter 2017–18: highest 2.24 m · 0 days above the normal rangeWinter 2019–20: highest 2.76 m · 4 days above the normal rangeWinter 2020–21: highest 3.15 m on 21 January 2021 · 7 days above the normal rangeWinter 2021–22: highest 2.86 m · 3 days above the normal rangeWinter 2022–23: highest 2.86 m · 4 days above the normal rangeWinter 2023–24: highest 2.50 m · 0 days above the normal rangeWinter 2024–25: highest 3.16 m on 1 January 2025 · 9 days above the normal rangeWinter 2025–26: highest 2.36 m · 0 days above the normal range’00–01’24–25’20–21Record 3.20 m, 2000Top of normal range
1990–912025–26
The highest days on record
  • 30 October 20003.20 m
  • 1 January 20253.16 m
  • 21 January 20213.15 m
  • 17 October 20243.00 m
  • 26 December 20152.97 m
  • 26 September 20122.97 m

The Sankey Brook has topped its normal range on 54 days since 1990, most in the winters of 2024–25 and 2020–21. By its highest day, the winter of 2025–26 was the 20th-highest of the 35.

Environment Agency Hydrology API, Causey Bridge (station 694039), daily maximum level; the record and normal range from the EA’s stage scale. Live river levels are on GOV.UK’s Check for flooding.

Flood warnings

No flood warning or alert is in force for Warrington · 144 warnings in 20 years

The Environment Agency has 18 flood warning areas and 5 alert areas reaching into the city; warnings since the service began in 2006.

Now: no flood warnings or alerts for Warrington (checked 6 November 2026, 00:07). Check for flooding on GOV.UK →
Warnings and alerts each year for areas in Warrington
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
Flood warning (flooding expected)Flood alert (flooding possible)

The warning area covering the most of Warrington, River Mersey from Runcorn to Woolston, has not had a flood warning since 2006. Of the 144 warnings, 69 were for Mersey Estuary at Arpley Bridge, Warrington and 22 for Mersey Estuary at Victoria Park, Knutsford Road, Warrington.

2014 had the most warnings (24); 2019 the most alerts (35). The most recent warning was on 8 October 2025.

Show the 23 warning and alert areas
AreaKindSince 2006Now
Mersey Estuary at Arpley Bridge, WarringtonWarning area69None
Mersey Estuary at Victoria Park, Knutsford Road, WarringtonWarning area22None
Areas closest to Sankey Brook at DallamWarning area12None
Sankey Brook at GeminiWarning area10None
Mersey Estuary at Bank Quay, WarringtonWarning area7None
Mersey Estuary at Howley, WarringtonWarning area5None
Mersey Estuary at Eastford Road, WarringtonWarning area5None
Mersey Estuary at Kingsway North, WarringtonWarning area4None
Wider area at risk from Sankey Brook at DallamWarning area3None
Areas closest to Sankey Brook at Sankey BridgesWarning area3None
Sankey Brook around areas of Gemini, Dallam, Bewsey, Longford, Orford, Great Sankey and PenkethWarning area1None
Mersey Estuary at Westy, WarringtonWarning area1None
Mersey Estuary at Knutsford Road, WarringtonWarning area1None
Mersey Estuary at Spectra Business Park at Slutchers LaneWarning area1None
Wider area at risk from Sankey Brook at Sankey BridgesWarning area0None
River Mersey from Runcorn to WoolstonWarning area0None
Mersey Estuary at Centre Park, WarringtonWarning area0None
Manchester Ship Canal at Lymm and ThelwallWarning area0None
Mersey Estuary at WarringtonAlert area169None
River Sankey catchment with St Helens and WarringtonAlert area40None
River Glaze catchment including Leigh and East WiganAlert area38None
River Ditton catchment including areas around Huyton-with-Roby and WidnesAlert area28None
Lower River Mersey including Warrington, Runcorn and Lymm areasAlert area4None

Environment Agency Historic Flood Warnings (first issues only, not updates; “flood watch” counted as an alert before 2011) and the real-time flood-monitoring API. Sign up for free warnings on GOV.UK or call Floodline, 0345 988 1188.

Radon

Parts of Warrington are in radon Affected Areas, at the low end

Radon is a natural radioactive gas from the ground; long exposure raises the risk of lung cancer. The atlas gives the chance that a home in each 1 km square is above the UK action level (200 Bq/m³).

SJ5586: Under 1% of homes above the action levelSJ5587: 1–3% of homes above the action levelSJ5588: 1–3% of homes above the action levelSJ5589: Under 1% of homes above the action levelSJ5590: Under 1% of homes above the action levelSJ5591: Under 1% of homes above the action levelSJ5686: Under 1% of homes above the action levelSJ5687: 1–3% of homes above the action levelSJ5688: 1–3% of homes above the action levelSJ5689: Under 1% of homes above the action levelSJ5690: Under 1% of homes above the action levelSJ5691: Under 1% of homes above the action levelSJ5787: 1–3% of homes above the action levelSJ5788: 1–3% of homes above the action levelSJ5789: Under 1% of homes above the action levelSJ5790: Under 1% of homes above the action levelSJ5791: Under 1% of homes above the action levelSJ5886: Under 1% of homes above the action levelSJ5887: Under 1% of homes above the action levelSJ5888: Under 1% of homes above the action levelSJ5889: Under 1% of homes above the action levelSJ5890: Under 1% of homes above the action levelSJ5891: Under 1% of homes above the action levelSJ5985: Under 1% of homes above the action levelSJ5986: Under 1% of homes above the action levelSJ5987: Under 1% of homes above the action levelSJ5988: Under 1% of homes above the action levelSJ5989: Under 1% of homes above the action levelSJ5990: Under 1% of homes above the action levelSJ5991: Under 1% of homes above the action levelSJ6084: Under 1% of homes above the action levelSJ6085: Under 1% of homes above the action levelSJ6086: Under 1% of homes above the action levelSJ6087: Under 1% of homes above the action levelSJ6088: Under 1% of homes above the action levelSJ6089: Under 1% of homes above the action levelSJ6090: Under 1% of homes above the action levelSJ6091: Under 1% of homes above the action levelSJ6092: Under 1% of homes above the action levelSJ6182: Under 1% of homes above the action levelSJ6183: Under 1% of homes above the action levelSJ6184: Under 1% of homes above the action levelSJ6185: Under 1% of homes above the action levelSJ6186: Under 1% of homes above the action levelSJ6187: Under 1% of homes above the action levelSJ6188: Under 1% of homes above the action levelSJ6189: Under 1% of homes above the action levelSJ6190: Under 1% of homes above the action levelSJ6191: Under 1% of homes above the action levelSJ6282: Under 1% of homes above the action levelSJ6283: Under 1% of homes above the action levelSJ6284: Under 1% of homes above the action levelSJ6285: Under 1% of homes above the action levelSJ6286: Under 1% of homes above the action levelSJ6287: Under 1% of homes above the action levelSJ6288: Under 1% of homes above the action levelSJ6289: Under 1% of homes above the action levelSJ6290: Under 1% of homes above the action levelSJ6291: Under 1% of homes above the action levelSJ6383: Under 1% of homes above the action levelSJ6384: Under 1% of homes above the action levelSJ6385: Under 1% of homes above the action levelSJ6386: Under 1% of homes above the action levelSJ6387: Under 1% of homes above the action levelSJ6388: Under 1% of homes above the action levelSJ6389: Under 1% of homes above the action levelSJ6390: Under 1% of homes above the action levelSJ6391: Under 1% of homes above the action levelSJ6392: Under 1% of homes above the action levelSJ6486: Under 1% of homes above the action levelSJ6487: Under 1% of homes above the action levelSJ6488: Under 1% of homes above the action levelSJ6489: Under 1% of homes above the action levelSJ6490: Under 1% of homes above the action levelSJ6491: Under 1% of homes above the action levelSJ6492: Under 1% of homes above the action levelSJ6493: Under 1% of homes above the action levelSJ6586: Under 1% of homes above the action levelSJ6587: Under 1% of homes above the action levelSJ6588: Under 1% of homes above the action levelSJ6589: Under 1% of homes above the action levelSJ6590: Under 1% of homes above the action levelSJ6591: Under 1% of homes above the action levelSJ6592: Under 1% of homes above the action levelSJ6593: Under 1% of homes above the action levelSJ6689: Under 1% of homes above the action levelSJ6691: Under 1% of homes above the action levelSJ6692: Under 1% of homes above the action levelSJ6693: Under 1% of homes above the action levelSJ6792: Under 1% of homes above the action levelSJ6793: Under 1% of homes above the action level© OpenStreetMap contributors · BGS/UKHSA
Under 1%1–3%
Share of the city’s area in each band
Under 1% of homes91%
1–3% of homes9%

9% of Warrington’s built-up area is in a radon Affected Area (1% of homes or more above the action level).

The squares are indicative: each takes the highest band found anywhere inside it, so most homes in a coloured square are below it. Only a three-month test in the home gives a real answer.

BGS/UKHSA Indicative Atlas of Radon in Great Britain, version 3. Check an address at UKradon.org.

Neighbours

Flood risk in the places around Warrington

Share of homes at high or medium and at low risk from rivers and the sea. Tap a town for its page.

Winwick: Hazard risk ACroft: Hazard risk ABurtonwood: Hazard risk B+Appleton Thorn: Hazard risk ANewton-le-Willows: Hazard risk B+Lymm: Hazard risk C+Culcheth: Hazard risk CWinwickCroftBurtonwoodAppleton ThornNewton-le-WillowsLymmCulchethWarrington
ABCD
TownPeopleHigh or mediumLowHazard
Warrington174,9683.2%11%C−
Winwick2,0620%0%A
Croft1,5200%0%A
Burtonwood3,5040%0.3%B+
Appleton Thorn1,3720%0%A
Newton-le-Willows24,6510%0.3%B+
Lymm11,5470.7%0.9%C+
Culcheth6,7221.4%1.1%C

Warrington has more homes at high or medium risk than any neighbour in the table.

Be ready

Get ready for what Warrington faces

Free warnings, what to do in a cloudburst, and what to check before you move.

Get the warnings
  • Sign up free for Environment Agency flood warnings by text, call or email.
  • Floodline: 0345 988 1188, 24 hours.
  • Warrington’s warning areas include River Mersey from Runcorn to Woolston and Sankey Brook around areas of Gemini, Dallam, Bewsey, Longford, Orford, Great Sankey and Penketh.
Sign up ↗
In a cloudburst
  • Surface water rises in minutes, often with no warning issued: stay out of underpasses and dips.
  • Keep the gullies and drains outside your home clear of leaves.
  • Report a blocked road drain to the council.
Radon
  • Test over three months, in a living room and a bedroom.
  • Above 200 Bq/m³, a small sump and fan usually fixes it.
  • New homes in radon areas are built with protection: basic from 3%, full from 10%.
UKradon ↗
Before you buy or rent in Warrington
  • Check the address on GOV.UK’s long-term flood risk service: it gives rivers and sea and surface water separately.
  • Ask whether the home has flooded or had a flood insurance claim; the TA6 property form asks the seller.
  • Homes built before 2009 can get flood cover through Flood Re, the government-backed scheme; newer homes can’t.
  • Check radon for the address on UKradon.org (a small fee) or ask the seller for a test result.
How to read these numbers

What this data can and can’t tell you

  • Defences are counted. Both agencies’ maps allow for flood defences and the chance they are overtopped or fail, so a town behind a defence scheme can show few homes at high risk and many at low risk.
  • Surface water is our estimate. Neither agency publishes a count of homes at risk from surface water, so we read each address on the map. A flat on a hill and a basement in a dip can share a postcode.
  • Past floods are what was recorded. The flood outlines come from surveys, aerial photographs and reports; many small floods, and most surface-water floods, were never mapped.
  • One town, many streets. Risk is street by street. Check a specific address on GOV.UK’s long-term flood risk service before you buy or rent.

Check the long-term flood risk for an address on GOV.UK →

Questions about flooding and hazards in Warrington

Does Warrington flood?

The last flood the Environment Agency recorded inside the city was in January 2025. 3.2% of homes are at high or medium risk from rivers and the sea on the Environment Agency’s maps, which allow for flood defences. About 4.3% of homes are at high or medium risk from surface water, when heavy rain overwhelms the drains. Warrington grades C− for hazard risk against UK towns.

Which parts of Warrington are at risk of flooding?

From rivers and the sea, the places the Environment Agency warns directly: Mersey Estuary at Arpley Bridge, Warrington, Mersey Estuary at Victoria Park, Knutsford Road, Warrington, Areas closest to Sankey Brook at Dallam and Sankey Brook at Gemini. Surface water can collect in low spots anywhere in the city. Check a specific address on GOV.UK’s long-term flood risk service.

When did Warrington last flood?

The recorded flood outlines inside the city run from 1978 to 2025 (12 years); the largest was in 2021. Flood warnings have been issued for parts of the city since 2006, most recently on 8 October 2025.

Is Warrington at risk of surface water flooding?

About 1.6% of homes are at high risk and 2.7% at medium risk from surface water, against 3.2% at high or medium risk from rivers and the sea. Surface water floods come with little warning, and the agencies don’t issue warnings for them.

Is radon a problem in Warrington?

9% of the city’s built-up area is in a radon Affected Area on the BGS/UKHSA atlas. Most homes are below it; a three-month test is the only way to know.

Are there flood warnings in Warrington now?

No flood warning or alert was in force near Warrington at 6 November 2026, 00:07. Live warnings are on GOV.UK’s Check for flooding service and Floodline, 0345 988 1188.

Contains Environment Agency information © Environment Agency and/or database right 2026. Contains British Geological Survey materials © UKRI 2026.

Sources: Environment Agency Risk of Flooding from Rivers and Sea, postcodes in areas at risk (June 2026); Natural Resources Wales Flood Risk Assessment Wales (May 2026); ONS Census 2021 households by postcode · Environment Agency Risk of Flooding from Surface Water (NaFRA2, 2025) and Natural Resources Wales Flood Risk Assessment Wales surface water and small watercourses, read at every address (ONS National Statistics UPRN Lookup, September 2026) and weighted by Census 2021 households by postcode · Environment Agency Recorded Flood Outlines and Natural Resources Wales historic flood map, inside the ONS 2022 built-up-area boundary · Environment Agency Hydrology API (daily maximum river level) and flood-monitoring stage scales · Environment Agency real-time flood-monitoring API · Environment Agency Historic Flood Warnings (January 2006 to June 2026) and flood warning and alert areas · BGS/UKHSA Indicative Atlas of Radon in Great Britain, version 3, by 1 km square · TownRatings grades: our own summary of the data, ranked against UK towns only. All under the Open Government Licence v3.0.

Contains public sector information licensed under the Open Government Licence v3.0. Contains HM Land Registry data © Crown copyright and database right 2026. Contains OS data © Crown copyright and database right 2026 (ONS boundaries). Northern Ireland: Source: NISRA; contains Land & Property Services data and Ordnance Survey of Northern Ireland information, © Crown copyright, licensed under the Open Government Licence v3.0. Scotland: contains National Records of Scotland data, Registers of Scotland data and SEPA data, © Crown copyright / © SEPA 2025, licensed under the Open Government Licence v3.0.