BIRMINGHAM CLIMATE INSIGHTS

Birmingham Flood Risk and Climate Data - Postcode Analysis

3 May 2026 - LocalRisk

Birmingham Flood Risk and Climate Data - Postcode Analysis

Birmingham's three rivers - the Tame, Rea and Cole - drain through a dense urban catchment. Flood risk sits across 23.5% of postcodes. Air quality is the bigger concern, with PM2.5 of 7.89 µg/m³ - above Manchester, Leeds, Bristol and Newcastle. Subsidence risk is zero across all 21,672 postcodes.

Environment Agency flood zone data, air quality, subsidence and heat projections for Birmingham mapped by postcode. Three rivers, 21,000 postcodes, zero su

Birmingham's three rivers carry real flood risk - but air quality is the bigger story

Three rivers drain through Birmingham's urban core: the Tame, the Rea, and the Cole. Add a dense cityscape with limited natural drainage and intense summer downpours, and flood risk sits across 23.5% of postcodes - roughly one in four.

Environment Agency flood zone data across all 21,672 Birmingham postcodes shows 3,056 fall within high flood risk areas. A further 2,037 sit in medium risk zones. That is 14.1% of postcodes at high risk and 9.4% at medium - placing Birmingham 51st nationally among councils with 5,000 or more postcodes. For England's second largest city, those are substantial numbers in absolute terms, even if the percentage sits below the most flood-exposed councils.

Birmingham's worst-affected postcodes

The River Rea flows north through Stirchley and Cotteridge - rising in the Waseley Hills south of Birmingham, it drains the city northward before joining the River Tame near Gravelly Hill. The B29/B30 corridor through Selly Park, Stirchley and Cotteridge contains some of the city's most flood-exposed addresses. B29 7BW and B29 7BG - in the Selly Park and northern Stirchley area, on the River Rea flood plain - each have 79 properties classified as high flood risk, with zero medium or low risk properties alongside them: every assessed property in those postcodes carries the highest EA classification.

The River Cole catchment in the east of the city adds to the picture. The Cole flows through Stechford (B33), Bordesley Green (B9), and Washwood Heath (B8) before joining the Tame - postcodes in those areas follow the Cole flood plain and carry elevated risk accordingly.

> Birmingham has 21,672 postcodes in total. Of those, 3,056 (14.1%) are high risk, 2,037 (9.4%) are medium risk, and 4,378 (20.2%) are low risk.

How Birmingham compares to other large English cities

Birmingham's 14.1% high flood risk rate sits in the middle of the national picture for major cities. Bristol (29.8%) and Wolverhampton (19.6%) carry considerably higher rates; Manchester (10.2%) comes in lower.

| Council | High Flood Risk % | Total Postcodes | |---|---|---| | Bristol | 29.8% | 11,746 | | Wolverhampton | 19.6% | 5,747 | | Birmingham | 14.1% | 21,672 | | Leeds | 13.8% | 20,755 | | Manchester | 10.2% | 14,241 |

_Source: Environment Agency flood zone data, analysed by LocalRisk._

Neighbouring West Midlands councils sit close. Walsall at 18.6% and Dudley at 14.9% carry higher rates than Birmingham. The Black Country's river network - the Stour and its tributaries running through post-industrial terrain - pushes those figures up.

Recent weather

Birmingham's annual rainfall is around 665mm under the Met Office 1991-2020 standard (Birmingham Airport station). That places it in the drier half of major UK cities - below Manchester (~850mm), Bristol (~782mm), and Newcastle (~650mm, Durham station) but above Cambridge (~548mm) and London (~563mm, Greenwich station).

On heat, observed data for 2023-2025 shows Birmingham averaged 9.7 days above 25°C per year. 2024 was the outlier: a cool wet summer brought just 4 hot days. 2023 and 2025 delivered 12 and 13 days respectively.

| Year | Hot Days (>25°C) | |---|---| | 2023 | 12 | | 2024 | 4 | | 2025 | 13 |

_Source: Open-Meteo Historical Weather Archive (ERA5 reanalysis), 2023-2025._

Climate projections

Met Office UKCP18 projections put Birmingham at around 26 days above 25°C as a central estimate for the 2021-2040 period - higher than Bristol (24 days) and above Leeds and Manchester (both 18 days), reflecting Birmingham's position in the warmer Midlands interior.

These are probabilistic projections from the Met Office UKCP18 ensemble under a high emissions scenario (RCP8.5, 50th percentile) - the same data that drives the risk scores on LocalRisk postcode pages. The full range of modelled outcomes is wide. Under lower emissions scenarios the central estimate would be materially less; under the high end of the ensemble it would be greater. The direction - more hot days and more intense heat events - is consistent across the range.

For a city with three river systems draining a dense urban catchment, more intense summer downpours create compounding pressure on drainage infrastructure. Wetter winters and hotter summers tax the same ageing pipe networks from different directions.

_Source: Met Office UKCP18 climate projections (2021-2040 period, RCP8.5, 50th percentile). Observed data: Open-Meteo ERA5 reanalysis, 2023-2025._

Air quality: the more pressing concern

Birmingham's average PM2.5 reading is 7.89 µg/m³ - Medium band nationally and above the 5 µg/m³ WHO annual guideline. It sits above Manchester (7.71 µg/m³), Leeds (7.36), Cambridge (7.39), Brighton (6.70), Bristol (6.60) and Newcastle (6.22). Among the major English cities in the LocalRisk dataset, only Leicester (7.92) records a higher figure.

The primary driver is road traffic. The A38, A34, and A45 corridors carry heavy volumes through the city. The West Midlands motorway network - the M6, M5, and M42 intersecting around and through Birmingham - contributes background particulate levels that push the council average above most peer cities. Postcodes close to major arterial routes and motorway junctions will sit above that 7.89 average; postcodes in greener residential areas will sit below it.

Subsidence: complete outlier

Birmingham sits on Triassic sandstone and mudstone - rock that does not shrink and swell with moisture in the way clay does. The data confirms it: zero percent of Birmingham postcodes carry probable or possible shrink-swell clay risk. Every postcode in the city is classified as improbable for subsidence.

London boroughs, large parts of the South East, Cambridge, and much of the East Midlands carry moderate to high subsidence exposure from London Clay and similar formations. Birmingham homeowners face none of those complications. Subsidence insurance issues and mortgage problems linked to clay movement simply do not feature in the city's postcode data.

Green space: 14.8% within 200 metres

One in seven hectares within 200 metres of the average Birmingham postcode qualifies as green space - 14.8%. That is below Bristol (18.6%) and broadly comparable to Manchester (14.7%).

Sutton Park, in the north of the city, is one of the largest urban parks in Europe and lifts scores for Sutton Coldfield postcodes. Cannon Hill Park benefits Moseley and Balsall Heath postcodes to the south. Postcodes in the city centre, the industrial east, and along the ring road score below average.

_Source: LocalRisk green space analysis using Ordnance Survey data._

For Birmingham buyers

EA flood zone classification means an area carries a meaningful probability of flooding from rivers, sea or surface water - not that any specific property will flood. For buyers, high-risk classification typically means higher insurance premiums, potential resale complications, and exposure to water damage.

Higher-risk areas follow the three river valleys: the Rea corridor through Selly Park, Stirchley and Cotteridge (B29-B30); the Cole catchment through Tyseley and Small Heath (B10-B11); and parts of the Tame flood plain in the north and east of the city. Lower-risk areas sit on higher ground: Edgbaston, Harborne, and Moseley on the southern ridge, and Sutton Coldfield in the north.

Air quality is worth checking at postcode level before buying. Addresses along the A38, A34, A45, and near motorway junctions will carry readings above the council average. Check any Birmingham postcode directly at localrisk.co.uk for a full five-risk breakdown.

Birmingham combines moderate flood exposure, above-average air quality concern, notable heat projections, and a subsidence profile cleaner than any comparable UK city.

Check your own postcode

You can check the flood, heat, air quality, and subsidence risk for any UK postcode - free - at localrisk.co.uk. Birmingham's full council breakdown, including a comparison of every postcode in the city, is at localrisk.co.uk/council/birmingham.

Data sources: Environment Agency flood zone and surface water risk data; Defra UK-AIR PM2.5 monitoring (2024 data, population-weighted LAD mean); British Geological Survey shrink-swell clay risk assessment; Met Office 1991-2020 station normals (Birmingham Airport); Open-Meteo Historical Weather Archive (ERA5 reanalysis, ECMWF), 2023-2025; Met Office UKCP18 climate projections (2021-2040 period, RCP8.5, 50th percentile). Analysis by LocalRisk. _Methodology: Annual rainfall uses Met Office 1991-2020 station normals (Birmingham Airport, ~665mm). Observed hot-day counts use Open-Meteo ERA5 reanalysis, 2023-2025. Climate projections use Met Office UKCP18; RCP8.5 is a high emissions scenario and the 50th percentile represents the central estimate - outcomes under lower emissions would be less severe. Days above 25°C are used as the hot-day threshold for consistent cross-city comparison._

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