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CHazard risk Grade
Flood & hazards in Reading · Environment Agency

In Reading, heavy rain puts more homes at risk than rivers or the sea: 4.2%, against 1%

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. Reading’s Hazard risk Grade is C: #10 of 30 in Berkshire.

1971worst recorded flood49flood warnings since 200638%in a radon Affected Area
In brief

What stands out about Reading’s hazards

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

Rain, more than the river4.2% of homes sit where heavy rain can flood the streets, against 1% at risk from rivers and the sea.Remembers 1971Floodwater covered 120 hectares of today’s Reading in 1971; 2,039 of today’s households live inside past flood outlines.49 flood warnings since 2006For the parts of Reading the Environment Agency warns directly; the most recent on 16 February 2026.
By hazard

What Reading faces

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

Rivers and the sea

1%of homes at high or medium risk
More than the typical UK town · more than 68% of towns
957 homes by the EA’s own count

Surface water

4.2%of homes at high or medium risk
More than 59% of UK towns
Rivers and sea: 1%

Past floods

15years with a recorded flood
Last recorded: November 2013
2,039 households inside past outlines

The River Kennet

0.23 mhighest in winter 2025–26 at Blakes Lock
34th-highest of 34 winters
Record 0.80 m, December 2000

Flood warnings

49flood warnings since 2006
222 flood alerts for the wider area
Last warning 16 February 2026

Radon

38%of the city in a radon Affected Area
Highest band here: 3–5% 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

Reading grades C for hazard risk

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

Homes at high or medium flood risk (1%)Fewer than 32% 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 Reading

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: 1947Recorded flood: 1968Recorded flood: 1971Recorded flood: 1974Recorded flood: 1977Recorded flood: 1981Recorded flood: 1990Recorded flood: 1991Recorded flood: 1992Recorded flood: 1993Recorded flood: 2000Recorded flood: 2002Recorded flood: 2007Recorded flood: 2008Recorded flood: 2013© OpenStreetMap contributors · EA NaFRA2
HighMediumLowrivers & seaHighMediumLowsurface waterReading’s built-up area

The river and sea risk follows the River Kennet, the River Thames and the River Loddon. 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

1% of Reading’s homes are at high or medium risk from rivers or the sea

The Environment Agency’s national map, allowing for defences. A further 3.2% are at low risk.

High risk0.4%of homes · 1 in 30 a year or more394 homes, EA count
Medium risk0.6%of homes · 1 in 30 to 1 in 100563 homes, EA count
Low risk3.2%of homes · 1 in 100 to 1 in 1,0003,105 homes, EA count
Where Reading sits among 3,735 UK towns
35%None
23%Under 0.5%
9%0.5–1%Reading
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; Reading has more than 68% of towns.

Towns its size: 30th of 45 from the fewest homes at risk
#TownPeopleHigh or med.
1Islington London216,3090%
2Camden London209,3420%
3Westminster London203,5710%
…
28Haringey London264,0690.8%
29Hackney London258,4640.8%
30Reading Berkshire203,7891%
31Barking and Dagenham London218,2361%
32Harrow London260,5341.3%
…
44Oxford Oxfordshire170,7994.7%
45Kingston upon Hull East Riding of Yorkshire270,8166.3%

UK towns of 143,000 to 285,000 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 4.2 times as many Reading 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 water4.2%
Rivers and the sea1%
0%7%14% of homes

About 2% of homes are at high risk of surface-water flooding (a 1 in 30 chance or more each year) and 2.2% at medium risk: roughly 3,290 households. A further 6.2% face a low risk from surface water. That is more than 59% of UK towns.

~3,290
households at high or medium risk
6.2%
of homes at low risk
59%
of UK towns have a smaller share
95,330
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

Reading has flooded in 15 recorded years since 1947, most of all in 1971

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

  1. 2013November 2013: River flooding recorded22 hectares inside today’s built-up area
  2. 2008January 2008: River flooding recorded1 hectare inside today’s built-up area
  3. 2007July 2007: River flooding recorded13 hectares inside today’s built-up area · Thames SE area
  4. 2002December 2002: River flooding recorded53 hectares inside today’s built-up area
  5. 2000January 2000: River flooding recorded10 hectares inside today’s built-up area
  6. 1993January 1993: River flooding recorded8 hectares inside today’s built-up area
Show all 15
  1. 1992January 1992: River flooding recorded36 hectares inside today’s built-up area
  2. 1991January 1991: River flooding recorded11 hectares inside today’s built-up area
  3. 1990January 1990: River flooding recorded11 hectares inside today’s built-up area
  4. 1981January 1981: River flooding recorded11 hectares inside today’s built-up area
  5. 1977January 1977: River flooding recorded14 hectares inside today’s built-up area
  6. 1974January 1974: River flooding recorded18 hectares inside today’s built-up area
  7. 1971January 1971: River flooding recorded120 hectares inside today’s built-up area
  8. 1968January 1968: River flooding recorded3 hectares inside today’s built-up area
  9. 1947January 1947: River flooding recorded113 hectares inside today’s built-up area
The worst: 1971120 ha

Floodwater covered 120 hectares of what is now Reading in 1971, the largest flood the record holds here (January).

2,039 of Reading’s households today live inside the outline of a recorded flood.

Since 1971, the largest recorded flood inside the city covered 53 hectares.

River levels

The River Kennet at Blakes Lock: highest 0.80 m, in December 2000

The highest level each winter (October to September) at the Environment Agency’s Blakes Lock gauge, since 1991. The river normally runs between 0.00 m and 0.20 m here.

Highest level each winter, metres
Winter 1991–92: highest 0.44 m · 15 days above the normal rangeWinter 1992–93: highest 0.31 m · 26 days above the normal rangeWinter 1993–94: highest 0.26 m · 20 days above the normal rangeWinter 1994–95: highest 0.39 m · 44 days above the normal rangeWinter 1995–96: highest 0.37 m · 53 days above the normal rangeWinter 1996–97: highest 0.43 m · 42 days above the normal rangeWinter 1997–98: highest 0.40 m · 40 days above the normal rangeWinter 1998–99: highest 0.44 m · 66 days above the normal rangeWinter 1999–00: highest 0.67 m on 26 October 1999 · 43 days above the normal rangeWinter 2000–01: highest 0.82 m on 14 December 2000 · 110 days above the normal rangeWinter 2002–03: highest 0.73 m on 3 January 2003 · 45 days above the normal rangeWinter 2003–04: highest 0.41 m · 24 days above the normal rangeWinter 2004–05: highest 0.32 m · 18 days above the normal rangeWinter 2005–06: highest 0.34 m · 23 days above the normal rangeWinter 2006–07: highest 0.39 m · 49 days above the normal rangeWinter 2007–08: highest 0.32 m · 36 days above the normal rangeWinter 2008–09: highest 0.37 m · 28 days above the normal rangeWinter 2009–10: highest 0.37 m · 104 days above the normal rangeWinter 2010–11: highest 0.30 m · 23 days above the normal rangeWinter 2011–12: highest 0.28 m · 9 days above the normal rangeWinter 2012–13: highest 0.39 m · 71 days above the normal rangeWinter 2013–14: highest 0.78 m on 9 February 2014 · 100 days above the normal rangeWinter 2014–15: highest 0.30 m · 40 days above the normal rangeWinter 2015–16: highest 0.32 m · 49 days above the normal rangeWinter 2016–17: highest 0.29 m · 28 days above the normal rangeWinter 2017–18: highest 0.31 m · 60 days above the normal rangeWinter 2018–19: highest 0.33 m · 33 days above the normal rangeWinter 2019–20: highest 0.34 m · 28 days above the normal rangeWinter 2020–21: highest 0.33 m · 20 days above the normal rangeWinter 2021–22: highest 0.35 m · 82 days above the normal rangeWinter 2022–23: highest 0.37 m · 58 days above the normal rangeWinter 2023–24: highest 0.71 m on 7 January 2024 · 64 days above the normal rangeWinter 2024–25: highest 0.34 m · 21 days above the normal rangeWinter 2025–26: highest 0.23 m · 6 days above the normal range’00–01’13–14’02–03Record 0.80 m, 2000Top of normal range
1991–922025–26
The highest days on record
  • 14 December 20000.82 m
  • 9 February 20140.78 m
  • 3 January 20030.73 m
  • 7 January 20240.71 m
  • 8 November 20000.70 m
  • 26 October 19990.67 m

The River Kennet has topped its normal range on 1,478 days since 1991, most in the winters of 2000–01 and 2009–10. By its highest day, the winter of 2025–26 was the 34th-highest of the 34.

Environment Agency Hydrology API, Blakes Lock (station 2298TH), 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 Reading · 49 warnings in 20 years

The Environment Agency has 8 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 Reading (checked 4 November 2026, 22:15). Check for flooding on GOV.UK →
Warnings and alerts each year for areas in Reading
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 Reading, Foudry Brook from Stratfield Mortimer to Green Park, has not had a flood warning since 2006. Of the 49 warnings, 17 were for River Thames at Purley Village and 11 for Properties closest to the River Kennet at the Burghfield, Southcote, Coley and Holybrook areas.

2014 had the most warnings (14); 2024 the most alerts (29). The most recent warning was on 16 February 2026.

Show the 13 warning and alert areas
AreaKindSince 2006Now
River Thames at Purley VillageWarning area17None
Properties closest to the River Kennet at the Burghfield, Southcote, Coley and Holybrook areasWarning area11None
River Kennet from Theale down to ReadingWarning area8None
River Loddon at Lower Earley and SindleshamWarning area4None
River Loddon at Winnersh and WoodleyWarning area4None
Properties closest to the River Thames from Scours Lane, Reading to Caversham LakesWarning area4None
River Thames at Reading and CavershamWarning area1None
Foudry Brook from Stratfield Mortimer to Green ParkWarning area0None
Lower River LoddonAlert area79None
River Thames from Pangbourne to PurleyAlert area40None
River Thames from Mapledurham to SonningAlert area39None
River Kennet from Thatcham down to ReadingAlert area32None
River Enborne and Foudry BrookAlert area32None

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 Reading 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).

SU6471: 1–3% of homes above the action levelSU6472: 1–3% of homes above the action levelSU6571: Under 1% of homes above the action levelSU6572: Under 1% of homes above the action levelSU6573: Under 1% of homes above the action levelSU6574: Under 1% of homes above the action levelSU6575: Under 1% of homes above the action levelSU6576: 1–3% of homes above the action levelSU6671: 1–3% of homes above the action levelSU6672: Under 1% of homes above the action levelSU6673: Under 1% of homes above the action levelSU6674: Under 1% of homes above the action levelSU6675: 1–3% of homes above the action levelSU6676: 1–3% of homes above the action levelSU6770: Under 1% of homes above the action levelSU6771: 1–3% of homes above the action levelSU6772: Under 1% of homes above the action levelSU6773: Under 1% of homes above the action levelSU6774: 1–3% of homes above the action levelSU6775: 1–3% of homes above the action levelSU6870: Under 1% of homes above the action levelSU6871: 1–3% of homes above the action levelSU6872: 1–3% of homes above the action levelSU6873: 3–5% of homes above the action levelSU6874: 3–5% of homes above the action levelSU6969: Under 1% of homes above the action levelSU6970: Under 1% of homes above the action levelSU6971: 1–3% of homes above the action levelSU6972: Under 1% of homes above the action levelSU6973: 3–5% of homes above the action levelSU6974: 3–5% of homes above the action levelSU7069: Under 1% of homes above the action levelSU7070: Under 1% of homes above the action levelSU7071: 1–3% of homes above the action levelSU7072: 1–3% of homes above the action levelSU7073: 3–5% of homes above the action levelSU7074: 3–5% of homes above the action levelSU7168: Under 1% of homes above the action levelSU7169: Under 1% of homes above the action levelSU7170: Under 1% of homes above the action levelSU7171: Under 1% of homes above the action levelSU7172: 1–3% of homes above the action levelSU7173: 1–3% of homes above the action levelSU7174: 3–5% of homes above the action levelSU7268: Under 1% of homes above the action levelSU7269: Under 1% of homes above the action levelSU7270: Under 1% of homes above the action levelSU7271: Under 1% of homes above the action levelSU7272: Under 1% of homes above the action levelSU7273: 1–3% of homes above the action levelSU7274: 3–5% of homes above the action levelSU7369: Under 1% of homes above the action levelSU7370: Under 1% of homes above the action levelSU7371: Under 1% of homes above the action levelSU7372: Under 1% of homes above the action levelSU7373: 1–3% of homes above the action levelSU7374: 3–5% of homes above the action levelSU7468: Under 1% of homes above the action levelSU7469: Under 1% of homes above the action levelSU7470: Under 1% of homes above the action levelSU7471: Under 1% of homes above the action levelSU7472: Under 1% of homes above the action levelSU7473: 1–3% of homes above the action levelSU7474: 3–5% of homes above the action levelSU7569: Under 1% of homes above the action levelSU7570: Under 1% of homes above the action levelSU7571: Under 1% of homes above the action levelSU7572: Under 1% of homes above the action levelSU7573: Under 1% of homes above the action levelSU7670: Under 1% of homes above the action levelSU7671: Under 1% of homes above the action level© OpenStreetMap contributors · BGS/UKHSA
Under 1%1–3%3–5%
Share of the city’s area in each band
Under 1% of homes62%
1–3% of homes27%
3–5% of homes11%

38% of Reading’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 Reading

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

Caversham: Hazard risk D−Shinfield: Hazard risk BSpencers Wood and Three Mile Cross: Hazard risk BSonning: Hazard risk C+Woodley: Hazard risk B−Theale: Hazard risk C−Winnersh: Hazard risk CCavershamShinfieldSpencers Wood and Three Mile CrossSonningWoodleyThealeWinnershReading
ABCD
TownPeopleHigh or mediumLowHazard
Reading203,7891%3.2%C
Caversham33,03813%7.1%D−
Shinfield5,4170.1%under 0.1%B
Spencers Wood and Three Mile Cross7,612under 0.1%0.2%B
Sonning1,6150.4%0.1%C+
Woodley28,0190.2%0.3%B−
Theale3,0531.7%0.1%C−
Winnersh8,9041.3%5.1%C

Caversham, 2 miles north, has the most homes at risk around Reading (13% at high or medium).

Be ready

Get ready for what Reading 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.
  • Reading’s warning areas include River Thames at Reading and Caversham and Foudry Brook from Stratfield Mortimer to Green Park.
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 Reading
  • 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 Reading

Does Reading flood?

The last flood the Environment Agency recorded inside the city was in November 2013. 1% 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 4.2% of homes are at high or medium risk from surface water, when heavy rain overwhelms the drains. Reading grades C for hazard risk against UK towns.

Which parts of Reading are at risk of flooding?

From rivers and the sea, the places the Environment Agency warns directly: River Thames at Purley Village, Properties closest to the River Kennet at the Burghfield, Southcote, Coley and Holybrook areas, River Kennet from Theale down to Reading and River Loddon at Lower Earley and Sindlesham. 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 Reading last flood?

The recorded flood outlines inside the city run from 1947 to 2013 (15 years); the largest was in 1971. Flood warnings have been issued for parts of the city since 2006, most recently on 16 February 2026.

Is Reading at risk of surface water flooding?

About 2% of homes are at high risk and 2.2% at medium risk from surface water, against 1% 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 Reading?

38% 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 Reading now?

No flood warning or alert was in force near Reading at 4 November 2026, 22:15. 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.