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C+Hazard risk Grade
Flood & hazards in Ealing · Environment Agency

In Ealing, heavy rain puts more homes at risk than rivers or the sea: 7.9%, against 0.6%

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 Ealing at C+: #15 of 33 in London.

1977worst recorded flood0flood warnings since 20060.8%at low risk
In brief

What stands out about Ealing’s hazards

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

Rain, more than the river7.9% of homes sit where heavy rain can flood the streets, against 0.6% at risk from rivers and the sea.Remembers 1977Floodwater covered 27 hectares of today’s Ealing in 1977; 517 of today’s households live inside past flood outlines.No flood warning since 2006The Environment Agency has 4 warning areas in Ealing and hasn’t had to issue a flood warning for any of them.Low radonEvery 1 km square over Ealing is in the lowest radon band: under 1% of homes above the action level.
By hazard

What Ealing faces

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

Rivers and the sea

0.6%of homes at high or medium risk
More than the typical UK town · more than 61% of towns
835 homes by the EA’s own count

Surface water

7.9%of homes at high or medium risk
More than 86% of UK towns
Rivers and sea: 0.6%

Past floods

1years with a recorded flood
Last recorded: January 1977
517 households inside past outlines

The River Brent

1.18 mhighest in winter 2025–26 at Greenford, Costons Lane
15th-highest of 36 winters
Record 1.75 m, September 1992

Flood warnings

0flood warnings since 2006
51 flood alerts for the wider area
Never warned

Radon

0%of the borough in a radon Affected Area
Highest band here: Under 1% 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

Ealing grades C+ for hazard risk

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

Homes at high or medium flood risk (0.6%)Fewer than 39% 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 Ealing

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: 1977© OpenStreetMap contributors · EA NaFRA2
HighMediumLowrivers & seaHighMediumLowsurface waterEaling’s built-up area

The river and sea risk follows the River Brent, the River Crane and the River Thames. Surface-water risk is spread across the borough, in dips, underpasses and along small streams, which is why more homes are exposed to it.

Rivers and the sea

0.6% of Ealing’s homes are at high or medium risk from rivers or the sea

The Environment Agency’s national map, allowing for defences. A further 0.8% are at low risk.

High risk0.3%of homes · 1 in 30 a year or more413 homes, EA count
Medium risk0.3%of homes · 1 in 30 to 1 in 100422 homes, EA count
Low risk0.8%of homes · 1 in 100 to 1 in 1,0001,148 homes, EA count
Where Ealing sits among 3,735 UK towns
35%None
23%Under 0.5%
9%0.5–1%Ealing
11%1–2%
11%2–5%
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; Ealing has more than 61% of towns.

Towns its size: 13th of 36 from the fewest homes at risk
#TownPeopleHigh or med.
1Southwark London307,0760%
2Newham London351,065under 0.1%
3Havering London259,4010.1%
…
11Brighton and Hove East Sussex277,0960.5%
12Liverpool Merseyside506,5640.6%
13Ealing London367,2710.6%
14Plymouth Devon266,9700.8%
15Haringey London264,0690.8%
…
35Nottingham Nottinghamshire299,7863.6%
36Kingston upon Hull East Riding of Yorkshire270,8166.3%

UK towns of 257,000 to 514,000 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 13.4 times as many Ealing 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 water7.9%
Rivers and the sea0.6%
0%14%28% of homes

About 4% of homes are at high risk of surface-water flooding (a 1 in 30 chance or more each year) and 3.9% at medium risk: roughly 10,620 households. A further 14% face a low risk from surface water. That is more than 86% of UK towns.

~10,620
households at high or medium risk
14%
of homes at low risk
86%
of UK towns have a smaller share
171,946
addresses read on the map

Our estimate: every address in the borough (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

Ealing has flooded in 1 recorded year since 1977

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

  1. 1977January 1977: River flooding recorded27 hectares inside today’s built-up area
The worst: 197727 ha

Floodwater covered 27 hectares of what is now Ealing in 1977, the largest flood the record holds here (January).

517 of Ealing’s households today live inside the outline of a recorded flood.

River levels

The River Brent at Greenford, Costons Lane: highest 1.75 m, in September 1992

The highest level each winter (October to September) at the Environment Agency’s Greenford, Costons Lane gauge (Greenford), since 1990. The river normally runs between 0.13 m and 1.11 m here.

Highest level each winter, metres
Winter 1990–91: highest 0.91 m · 0 days above the normal rangeWinter 1991–92: highest 1.75 m on 23 September 1992 · 4 days above the normal rangeWinter 1992–93: highest 1.16 m · 1 days above the normal rangeWinter 1993–94: highest 1.50 m on 13 October 1993 · 2 days above the normal rangeWinter 1994–95: highest 1.12 m · 1 days above the normal rangeWinter 1995–96: highest 1.05 m · 0 days above the normal rangeWinter 1996–97: highest 1.12 m · 1 days above the normal rangeWinter 1997–98: highest 1.02 m · 0 days above the normal rangeWinter 1998–99: highest 1.11 m · 1 days above the normal rangeWinter 1999–00: highest 1.09 m · 0 days above the normal rangeWinter 2000–01: highest 1.67 m on 30 October 2000 · 7 days above the normal rangeWinter 2001–02: highest 1.28 m · 2 days above the normal rangeWinter 2002–03: highest 1.24 m · 3 days above the normal rangeWinter 2003–04: highest 1.23 m · 1 days above the normal rangeWinter 2004–05: highest 0.98 m · 0 days above the normal rangeWinter 2005–06: highest 0.79 m · 0 days above the normal rangeWinter 2006–07: highest 1.44 m on 20 July 2007 · 1 days above the normal rangeWinter 2007–08: highest 1.03 m · 0 days above the normal rangeWinter 2008–09: highest 1.33 m · 2 days above the normal rangeWinter 2009–10: highest 1.13 m · 2 days above the normal rangeWinter 2010–11: highest 1.14 m · 1 days above the normal rangeWinter 2011–12: highest 1.03 m · 0 days above the normal rangeWinter 2012–13: highest 1.10 m · 0 days above the normal rangeWinter 2013–14: highest 1.00 m · 0 days above the normal rangeWinter 2014–15: highest 1.54 m on 26 August 2015 · 1 days above the normal rangeWinter 2015–16: highest 1.05 m · 0 days above the normal rangeWinter 2016–17: highest 0.95 m · 0 days above the normal rangeWinter 2017–18: highest 1.33 m · 1 days above the normal rangeWinter 2018–19: highest 1.07 m · 0 days above the normal rangeWinter 2019–20: highest 0.99 m · 0 days above the normal rangeWinter 2020–21: highest 1.37 m · 3 days above the normal rangeWinter 2021–22: highest 1.16 m · 1 days above the normal rangeWinter 2022–23: highest 1.50 m on 3 November 2022 · 4 days above the normal rangeWinter 2023–24: highest 1.68 m on 23 September 2024 · 5 days above the normal rangeWinter 2024–25: highest 1.42 m · 1 days above the normal rangeWinter 2025–26: highest 1.18 m · 1 days above the normal range’91–92’23–24’00–01Record 1.75 m, 1992Top of normal range
1990–912025–26
The highest days on record
  • 23 September 19921.75 m
  • 23 September 20241.68 m
  • 30 October 20001.67 m
  • 26 August 20151.54 m
  • 3 November 20221.50 m
  • 13 October 19931.50 m

The River Brent has topped its normal range on 46 days since 1990, most in the winters of 2000–01 and 2023–24. By its highest day, the winter of 2025–26 was the 15th-highest of the 36.

Environment Agency Hydrology API, Greenford, Costons Lane (station 3870TH), 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 Ealing · 0 warnings in 20 years

The Environment Agency has 4 flood warning areas and 3 alert areas reaching into the borough; warnings since the service began in 2006.

Now: no flood warnings or alerts for Ealing (checked 4 November 2026, 10:18). Check for flooding on GOV.UK →
Warnings and alerts each year for areas in Ealing
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)

None of Ealing’s 4 flood warning areas has had a flood warning since the service began in 2006.

Show the 7 warning and alert areas
AreaKindSince 2006Now
River Brent in the London Borough of BrentWarning area0None
Yeading Brook at HillingdonWarning area0None
River Brent in the London Boroughs of Ealing and HounslowWarning area0None
Tidal Thames at ChiswickWarning area0None
River Brent from Hendon to BrentfordAlert area27None
Fluvial River CraneAlert area22None
Tidal Thames in the boroughs of Kensington and Chelsea, Hammersmith and Fulham, Ealing and HounslowAlert area2None

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

Ealing is in the lowest radon band

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).

TQ1078: Under 1% of homes above the action levelTQ1079: Under 1% of homes above the action levelTQ1082: Under 1% of homes above the action levelTQ1083: Under 1% of homes above the action levelTQ1178: Under 1% of homes above the action levelTQ1179: Under 1% of homes above the action levelTQ1180: Under 1% of homes above the action levelTQ1182: Under 1% of homes above the action levelTQ1183: Under 1% of homes above the action levelTQ1184: Under 1% of homes above the action levelTQ1278: Under 1% of homes above the action levelTQ1279: Under 1% of homes above the action levelTQ1280: Under 1% of homes above the action levelTQ1281: Under 1% of homes above the action levelTQ1282: Under 1% of homes above the action levelTQ1283: Under 1% of homes above the action levelTQ1284: Under 1% of homes above the action levelTQ1285: Under 1% of homes above the action levelTQ1378: Under 1% of homes above the action levelTQ1379: Under 1% of homes above the action levelTQ1380: Under 1% of homes above the action levelTQ1381: Under 1% of homes above the action levelTQ1382: Under 1% of homes above the action levelTQ1383: Under 1% of homes above the action levelTQ1384: Under 1% of homes above the action levelTQ1385: Under 1% of homes above the action levelTQ1479: Under 1% of homes above the action levelTQ1480: Under 1% of homes above the action levelTQ1481: Under 1% of homes above the action levelTQ1482: Under 1% of homes above the action levelTQ1483: Under 1% of homes above the action levelTQ1484: Under 1% of homes above the action levelTQ1485: Under 1% of homes above the action levelTQ1578: Under 1% of homes above the action levelTQ1579: Under 1% of homes above the action levelTQ1580: Under 1% of homes above the action levelTQ1581: Under 1% of homes above the action levelTQ1582: Under 1% of homes above the action levelTQ1583: Under 1% of homes above the action levelTQ1584: Under 1% of homes above the action levelTQ1585: Under 1% of homes above the action levelTQ1678: Under 1% of homes above the action levelTQ1679: Under 1% of homes above the action levelTQ1680: Under 1% of homes above the action levelTQ1681: Under 1% of homes above the action levelTQ1682: Under 1% of homes above the action levelTQ1683: Under 1% of homes above the action levelTQ1684: Under 1% of homes above the action levelTQ1685: Under 1% of homes above the action levelTQ1778: Under 1% of homes above the action levelTQ1779: Under 1% of homes above the action levelTQ1780: Under 1% of homes above the action levelTQ1781: Under 1% of homes above the action levelTQ1782: Under 1% of homes above the action levelTQ1783: Under 1% of homes above the action levelTQ1784: Under 1% of homes above the action levelTQ1879: Under 1% of homes above the action levelTQ1880: Under 1% of homes above the action levelTQ1881: Under 1% of homes above the action levelTQ1882: Under 1% of homes above the action levelTQ1883: Under 1% of homes above the action levelTQ1978: Under 1% of homes above the action levelTQ1979: Under 1% of homes above the action levelTQ1980: Under 1% of homes above the action levelTQ1981: Under 1% of homes above the action levelTQ1982: Under 1% of homes above the action levelTQ1983: Under 1% of homes above the action levelTQ2078: Under 1% of homes above the action levelTQ2079: Under 1% of homes above the action levelTQ2080: Under 1% of homes above the action levelTQ2081: Under 1% of homes above the action levelTQ2082: Under 1% of homes above the action levelTQ2083: Under 1% of homes above the action levelTQ2178: Under 1% of homes above the action levelTQ2179: Under 1% of homes above the action levelTQ2180: Under 1% of homes above the action levelTQ2181: Under 1% of homes above the action levelTQ2182: Under 1% of homes above the action levelTQ2183: Under 1% of homes above the action level© OpenStreetMap contributors · BGS/UKHSA
Under 1%
Share of the borough’s area in each band
Under 1% of homes100%

Every 1 km square over Ealing is in the lowest band: fewer than 1 in 100 homes are expected to be above the action level.

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

Neighbours

Flood risk in the places around Ealing

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

Brent: Hazard risk CHounslow: Hazard risk B−Hillingdon: Hazard risk CHarrow: Hazard risk CRichmond upon Thames: Hazard risk C−Hammersmith and Fulham: Hazard risk BKensington and Chelsea: Hazard risk BBrentHounslowHillingdonHarrowRichmond upon ThamesHammersmith and FulhamKensington and ChelseaEaling
ABCD
TownPeopleHigh or mediumLowHazard
Ealing367,2710.6%0.8%C+
Brent340,6111.5%2.1%C
Hounslow286,5910.3%0.9%B−
Hillingdon307,0891.3%2.6%C
Harrow260,5341.3%1.8%C
Richmond upon Thames192,8882%6.5%C−
Hammersmith and Fulham182,187under 0.1%0%B
Kensington and Chelsea143,348under 0.1%0%B

Richmond upon Thames, 4.9 miles south, has the most homes at risk around Ealing (2% at high or medium).

Be ready

Get ready for what Ealing 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.
  • Ealing’s warning areas include River Brent in the London Boroughs of Ealing and Hounslow and Tidal Thames at Chiswick.
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.
When the river rises
  • Never walk or drive through floodwater: 30 cm of moving water can float a car.
  • Move valuables, papers and medicines upstairs.
  • Turn off gas, electricity and water if you’re told to.
Before you buy or rent in Ealing
  • 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.
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 Ealing

Does Ealing flood?

The last flood the Environment Agency recorded inside the borough was in January 1977. 0.6% 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 7.9% of homes are at high or medium risk from surface water, when heavy rain overwhelms the drains. Ealing grades C+ for hazard risk against UK towns.

Which parts of Ealing are at risk of flooding?

From rivers and the sea, the places the Environment Agency warns directly: River Brent in the London Boroughs of Ealing and Hounslow, Tidal Thames at Chiswick, River Brent in the London Borough of Brent and Yeading Brook at Hillingdon. Surface water can collect in low spots anywhere in the borough. Check a specific address on GOV.UK’s long-term flood risk service.

When did Ealing last flood?

The recorded flood outlines inside the borough run from 1977 to 1977 (1 years); the largest was in 1977.

Is Ealing at risk of surface water flooding?

About 4% of homes are at high risk and 3.9% at medium risk from surface water, against 0.6% 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 Ealing?

Not by the atlas: every 1 km square over Ealing is in the lowest band, where fewer than 1 in 100 homes are expected to be above the action level.

Are there flood warnings in Ealing now?

No flood warning or alert was in force near Ealing at 4 November 2026, 10:18. 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.