What is a physical climate risk assessment?

A check of how weather and climate, now and in the future, could affect each place your business works from: mainly flooding from rivers, the sea and surface water, and heat. For each site you record the risk, what it would do to the business and what you are doing about it.

Is a climate risk assessment a legal requirement?

Not for most UK businesses. Listed companies report climate risks under FCA rules, which move to UK SRS for accounting periods from 1 January 2027, and the largest companies and LLPs report under the Companies Act. Everyone else is usually asked by customers and in tenders rather than by law.

Where do I check flood risk for a site?

In England, the Environment Agency's Check your long term flood risk service, which now uses the National Flood Risk Assessment (NaFRA) data published in January 2025. In Scotland, SEPA's flood maps; in Wales, Natural Resources Wales's Flood Risk Assessment Wales map; in Northern Ireland, DfI Rivers' Flood Maps (NI).

Do the flood maps tell me whether my building will flood?

No. All four services show the risk for an area, not a specific property. Record the result as area risk, and add what you know about the building itself, such as floor levels, past flooding and where stock or equipment sits.

How do I assess heat risk?

Start from the Met Office UK Climate Projections (UKCP18), which project hotter, drier summers and more frequent hot spells. Then look at each site: the building, whether it has cooling, outdoor or heavy work, and stock or processes that suffer in heat. There is no legal maximum workplace temperature, but employers must keep it reasonable.

How often should I update it?

Once a year is a sensible rhythm, alongside your carbon report, and whenever you open, move or close a site. The flood map services are updated from time to time, so check the date of the data you used.

Climate risk assessment for UK businesses: flood, heat and what customers ask

A practical climate risk assessment for a UK business takes each site in turn, checks its flood risk from rivers, the sea and surface water on the official map for its nation (in England, the Environment Agency's service built on the National Flood Risk Assessment published in January 2025), adds heat exposure from the Met Office's UKCP18 projections, and records the impact and your response. That one table answers most climate risk questions in tenders and feeds a TCFD-style or UK SRS S2 disclosure.

Updated 19 October 2026 by the Carbon Recycling team. Figures use the official UK government conversion factors and are checked against the current gov.uk guidance.

What this guide covers

Climate risk comes in two kinds. Physical risk is the weather and climate itself: a flooded unit, a heatwave that stops work. Transition risk comes from the move to a low-carbon economy: new rules, customer requirements and costs. Our post on climate risk and the TCFD pillars explains both and how to answer a customer in one page. This guide is the practical part underneath it: how to assess the physical risk at each of your sites, write it down and keep it current.

It is written for businesses of every size. A sole trader with one workshop can do it in an hour. A group with dozens of sites does the same thing more times, and the table at the end of step 4 scales.

Step 1: list your sites

For each place the business depends on, write down:

the name, full address and postcode;
what happens there (office, shop, warehouse, workshop, depot, data room) and roughly how many people work there;
what would stop if it were out of use for a week, and whether work could move elsewhere;
anything that is hard to replace: stock, machinery, servers, records, refrigerated goods.

Include places you rent and places you rely on but don't run, such as a key supplier's factory or a single route your deliveries depend on. You can assess those more lightly, but they are often where the real exposure is.

Step 2: check flood risk today

Each UK nation has its own official flood map. All four are free and work from a postcode or a map. They show the chance of flooding in an area, not whether a particular building will flood, so treat the result as area risk. Our step-by-step post on how to check the flood risk for your business premises walks through each one.

Nation	Service	Flood sources shown	How likelihood is banded
England	Check your long term flood risk (Environment Agency)	Rivers and the sea, surface water, reservoirs, and groundwater where data is available	High: more than 3.3% a year. Medium: 1% to 3.3%. Low: 0.1% to 1%. Very low: less than 0.1%
Scotland	SEPA flood maps	Rivers, the sea and surface water, now and with climate change	High: at least 10% a year. Medium: at least 0.5%. Low: at least 0.1%
Wales	Flood Risk Assessment Wales map (Natural Resources Wales)	Rivers, the sea, surface water and small watercourses, and reservoirs	High, medium, low or very low. For rivers and surface water, high is more than 1 in 30 (3.3%) a year
Northern Ireland	Flood Maps (NI) (DfI Rivers)	Rivers, the sea and surface water, with detailed maps for 69 areas and broad-scale maps elsewhere	Shown as flood extents for set chances of flooding, not a single risk rating

The bands are not the same across the nations. SEPA's "high" means at least a 10% chance each year, while in England and Wales "high" means more than 3.3% (1 in 30). If you have sites in more than one nation, record the percentage or the "1 in" figure as well as the label, so the sites can be compared.

Look at each source of flooding separately. They have different causes and different fixes:

Rivers and the sea. The England results take account of flood defences and their condition. Defences reduce the chance of flooding but can be overtopped or fail, which Natural Resources Wales points out on its results page too.
Surface water. Heavy rain that drains can't carry away. The Environment Agency's 2024 assessment found around 4.6 million properties in England in areas at risk from surface water, more than from rivers and the sea (around 2.4 million). Many sites a long way from any river are on this map.
Reservoirs and groundwater. Shown in England (groundwater only where data exists). Reservoir flooding is shown as a worst case if a large reservoir failed, not as a likelihood.

None of the maps shows flooding from blocked drains, burst pipes or overwhelmed sewers. If a site has flooded that way before, add it to your notes yourself.

Step 3: check how the risk changes with climate change

A climate risk assessment looks forward, so note the future picture as well as today's. In England, the Environment Agency's new National Flood Risk Assessment, sometimes called NaFRA2, was published on 28 January 2025. It combines thousands of local flood models with a new national model, shows likely flood depths, and for the first time includes scenarios based on the UK Climate Projections (UKCP18). The climate change datasets cover roughly 2036 to 2069 for rivers and the sea and 2040 to 2060 for surface water, and the Check your long term flood risk service shows how climate change might increase the chance of flooding in an area.

The scale is worth knowing. The Environment Agency estimates that 6.3 million properties in England are in areas at risk of flooding from rivers, the sea or surface water today, and that with climate change this could rise to around 8 million, about one in four properties, by the middle of the century. SEPA's maps also show future flood risk with climate change. For Wales and Northern Ireland, record today's result and note that you will check again as the maps are updated.

Step 4: add heat

Heat has no postcode map like flooding, so start from the Met Office's UK Climate Projections (UKCP18). The headline findings, updated in August 2022, say the UK is projected to have hotter, drier summers and warmer, wetter winters. In a high emissions scenario, average summer warming by 2070 is 1.3°C to 5.1°C, and hot spells (two or more days above 30°C) rise from an average of 0.2 a year today to around 4 a year by the 2070s in the most detailed projections. The Met Office puts the chance of a summer as hot as 2018 at 12% to 25% now, rising to around 50% to 60% by mid-century.

Then ask, for each site:

Does the building overheat now? Large glazed offices, metal-roofed units and top-floor rooms usually do.
Is there cooling, and what would it cost to run or add?
Do people work outdoors, drive, or do heavy work? Heat slows or stops it.
Is there stock, food, medicine, IT equipment or a process that fails in heat?

HSE says there is no law for a maximum working temperature, but employers must keep the temperature at a comfortable level and provide clean, fresh air. Hotter summers make that harder and more expensive, which is a real business impact to record. Cooling also adds electricity use, which shows up in your carbon footprint.

Step 5: record it, one row per site

Keep it in one table. For each site, rate how likely each hazard is (from the map band, or your judgement for heat) and how bad the impact would be, then say what you do about it and who owns it. An illustration for a business with three sites:

Site	Rivers and sea	Surface water	With climate change	Heat	Impact if hit	What we do
Head office (town centre)	Very low	Low	Surface water rises to medium	High: glazed, no cooling	Staff work from home; low	Laptops for all staff; review blinds and ventilation before summer
Warehouse (river valley)	Medium	Medium	Rivers and sea rises to high	Medium: metal roof	All dispatch stops; high	Stock on racking above 60cm; signed up to flood warnings; flood plan tested yearly
Depot (outskirts)	Very low	Very low	No change	Medium: drivers outdoors	Slower rounds; medium	Hot weather working rules; earlier start times in heatwaves

Add the date you checked and the name and date of the data (for example "Environment Agency long term flood risk, checked 19 October 2026"). Keep a screenshot of each result. It shows a customer or auditor where the rating came from, and it lets you see what changed next year.

The illustration shows the usual pattern: the site at highest risk is the one the business can least do without. That is where actions such as a flood plan, raised storage, a second site or insurance cover earn their keep. The Environment Agency notes that its flood risk data was not designed for setting insurance premiums, so talk to your broker about the cover itself.

Step 6: use it in reports and tenders

The same table feeds three things:

A TCFD-style disclosure. The site table is the evidence for the "strategy" and "risk management" pillars: which risks you face, over what time frame, and how you find and manage them. Our TCFD post has the one-page structure.
UK SRS S2. The government published UK SRS S1 and S2 on 25 February 2026. Under the FCA's final rules, UK listed companies report against them on a comply or explain basis for accounting periods starting on or after 1 January 2027, with first reports in 2028. S2 asks for climate-related risks and opportunities, including physical risks, and their effect on the company's business model and value chain, which is why listed customers ask their suppliers. See the UK SRS guide and what UK SRS S2 customers ask suppliers.
Tenders and questionnaires. Questions such as "have you assessed the climate risks to your operations?" are answered straight from the table. Our post on climate risk questions in tenders has model answers.

Transition risks sit alongside these. Your carbon footprint is the measure customers use for them, and new rules can turn into costs: from 1 January 2027, for example, importers of steel, aluminium, cement, fertiliser and hydrogen face the UK CBAM. If that applies to you, see the UK CBAM guide.

What this assessment can't tell you

Whether a particular building will flood. The maps are area risk.
Whether you can build or extend. In England the Environment Agency says its long term flood risk information for rivers, sea and surface water is not suitable for planning, and points to the Flood map for planning. Natural Resources Wales says the same of its map.
A full scenario analysis. Large companies reporting under UK SRS S2 use climate scenarios across the business. For most suppliers, a site-by-site table with a forward look is a proportionate answer.

How Carbon Recycling helps

Carbon Recycling already keeps a record of each of your sites, with its postcode, and produces a carbon report per site alongside your SECR report and Carbon Reduction Plan. Starter covers 2 sites, Growth (£149 + VAT a month) covers 10, and Enterprise (£399 + VAT a month) covers 100 sites, including sites outside the UK.

The Climate risk add-on, coming soon, adds flood and heat risk for each of your sites, with a climate risk summary you can put in a tender or a TCFD-style report. If a customer questionnaire is what prompted this, the free supplier questionnaire answer bankcovers the carbon questions that usually sit next to the climate risk ones.

Where this fits

Start free: Supplier questionnaire answer bank
The plan: Growth, £149 + VAT a month. Up to 10 sites and 10 users. With more sites, or sites outside the UK, Enterprise covers 100 sites.
The add-on: Climate risk, first 10 sites free, then £5 + VAT a site a year, coming soon. Flood and heat risk for each of your sites, with a climate risk summary for tenders or a TCFD-style report.
Also: CBAM pack. If you import steel, aluminium, cement, fertiliser or hydrogen, work out the embedded emissions and the UK CBAM charge.

Including VAT at 20%: Growth £178.80 a month; Climate risk first 10 sites free, then £6 a site a year. Each add-on is its own subscription on top of a paid plan: a 12-month minimum, paid monthly, or yearly upfront for 10 months' price. The 14-day free trial lets you add data and see your reports, but printing, saving and downloading need a paid plan.