UK rainfall by region and what it means for flat roofs
Updated 23 October 2026 · SEO Dons Editorial
How much rain falls in each UK region?
The Met Office’s 1991 to 2020 averages put the range at about 527 mm a year at Shoeburyness Landwick, an Essex station, to about 2,697 mm at Capel Curig No 3 in Wales. The table gives two climate stations for each English region, Wales, Scotland and Northern Ireland, one in a drier spot and one wetter or more exposed where the station list allows. These are station figures, not regional averages, so read each row as an example of the range. “Wet days” are days with 1 mm or more of rain.
| Region | Met Office station | Annual rainfall (mm) | Wet days a year |
|---|---|---|---|
| North East | Tynemouth | 608 | 116 |
| North East | Redesdale Camp | 941 | 159 |
| North West | Blackpool Squires Gate | 886 | 147 |
| North West | Shap | 1,863 | 174 |
| Yorkshire and the Humber | Church Fenton | 620 | 116 |
| Yorkshire and the Humber | Malham Tarn | 1,587 | 184 |
| East Midlands | Sutton Bonington | 630 | 118 |
| Northamptonshire (East Midlands) | Northampton Moulton Park | 649 | 118 |
| West Midlands | Shawbury | 683 | 132 |
| West Midlands | Winterbourne (University of Birmingham) | 809 | 133 |
| East of England | Shoeburyness Landwick | 527 | 102 |
| East of England | Cambridge NIAB | 559 | 107 |
| London | Kew Gardens | 627 | 114 |
| South East | Eastbourne | 793 | 116 |
| South West | Yeovilton | 730 | 126 |
| South West | Camborne | 1,076 | 155 |
| Wales | Cardiff Bute Park | 1,203 | 153 |
| Wales | Capel Curig No 3 | 2,697 | 206 |
| Scotland | Edinburgh Gogarbank | 784 | 137 |
| Scotland | Eskdalemuir | 1,827 | 194 |
| Northern Ireland | Aldergrove | 872 | 161 |
| Northern Ireland | Ballypatrick Forest | 1,326 | 196 |
Each region has its own roofing context in the linked pages, and the locations hub lists every area the site covers. Northern Ireland has no page of its own yet, so its row links to the building control guide.
Where are the wettest and driest places in the UK?
The Met Office says the wettest parts of the UK are in mountainous regions, with observation sites in Snowdonia, the Lake District and the Scottish Highlands “all receiving more than 4 metres of rainfall in a year”. In the table, Capel Curig No 3 (2,697 mm), Shap (1,863 mm), Eskdalemuir (1,827 mm) and Malham Tarn (1,587 mm) are the upland end. The pattern is a divide between the north-west and south-east: mountains force the prevailing westerly winds to rise, which cools the air and enhances cloud and rain.
The driest stations are in the east and south-east. Among the stations looked up for this guide, Shoeburyness Landwick (527 mm), Cambridge NIAB (559 mm) and Kew Gardens (627 mm) record the lowest annual totals. That is a statement about this station list, not a claim about every site in the UK.
Does annual rainfall decide how a flat roof is drained?
Not on its own. A roof has to shed a storm, and short bursts of rain are not confined to wet regions. Met Office records include 92 mm in 60 minutes at Maidenhead in Berkshire in July 1901, 80 mm in 30 minutes at Eskdalemuir in June 1953 and 169 mm in 155 minutes at Hampstead in August 1975. The 60-minute record sits in the lower-rainfall south-east, not on a mountain.
So a drier region does not excuse weak drainage. Falls and outlets are designed for the storm, and BS 6229:2025, which replaced the 2018 edition, made major updates to its design clause, especially the sub-clause on roof falls to achieve drainage. The ponding guide explains the falls rules. On a re-roof, ask the designer to state the design rainfall used, how many outlets serve each area and what happens if one blocks.
How do more wet days change a re-roof programme?
Capel Curig No 3 records about 206 wet days a year against about 102 at Shoeburyness Landwick, roughly twice as many. Wet days are not the same as unworkable days, but they set the odds on open-deck time. Employers must ensure work at height is “carried out only when the weather conditions do not jeopardise the health or safety of persons involved in the work”, a duty found in the Work at Height Regulations 2005 for England, Wales and Scotland and in the Northern Ireland version of 2005.
| Annual rainfall in the table | Stations | Questions for the programme and specification |
|---|---|---|
| Under 700 mm | Shoeburyness, Cambridge NIAB, Tynemouth, Kew Gardens, Church Fenton, Sutton Bonington, Northampton, Shawbury | Fewer wet days, but storm drainage still needs checking; confirm the temporary weathering plan for any open area |
| 700 mm to 1,000 mm | Yeovilton, Edinburgh Gogarbank, Eastbourne, Winterbourne, Blackpool Squires Gate, Aldergrove, Redesdale Camp | A moderate allowance for weather delay; check outlets and overflows before the covering is laid |
| Over 1,000 mm | Camborne, Cardiff Bute Park, Ballypatrick Forest, Malham Tarn, Eskdalemuir, Shap, Capel Curig No 3 | Plan for frequent interruptions; phase the work so each section is made weathertight the same day |
The bands are this guide’s own grouping of the table, not a Met Office or regulatory classification. The temporary roofs guide covers keeping a building dry while the covering is off.
Is the pattern changing?
The Met Office’s State of the UK Climate 2025 report, published on 15 July 2026, says the winter half-year (October to March) for 2016 to 2025 was 3% wetter than 1991 to 2020 and 13% wetter than 1961 to 1990. Months with twice the 1961 to 1990 average rainfall between October and March have approximately doubled. The 1991 to 2020 figures in the table are therefore already a little behind recent winters, which is a reason to treat design rainfall and winter programmes cautiously.
Wind is the other weather input to a roof specification: see UK wind exposure and flat roof uplift. If you are comparing contractors in a particular region, you can send an enquiry through the site’s form.
Sources
- Met Office, UK climate averages (location-specific long-term averages), 1991-2020 tables for the stations in the table: Tynemouth, Redesdale Camp, Blackpool Squires Gate, Shap, Church Fenton, Malham Tarn, Sutton Bonington, Northampton Moulton Park, Shawbury, Winterbourne (University of Birmingham), Shoeburyness Landwick, Cambridge NIAB, Kew Gardens, Eastbourne, Yeovilton, Camborne, Cardiff Bute Park, Capel Curig No 3, Edinburgh Gogarbank, Eskdalemuir, Aldergrove, Ballypatrick Forest, checked 22 October 2026
- Met Office: How much does it rain in the UK?, UK climate extremes and State of the UK Climate (2025 report published 15 July 2026), checked 22 October 2026
- BSI Knowledge: BS 6229:2025 (published 16 December 2025), checked 22 October 2026
- legislation.gov.uk: Work at Height Regulations 2005, regulation 4 and Work at Height Regulations (Northern Ireland) 2005, regulation 4, checked 22 October 2026
Common questions
Are the figures regional averages?
No. Each row is a Met Office climate station for 1991 to 2020, chosen to show the spread within a region. A site a few miles from a station, or at a different height, can record noticeably different rainfall.
Why use 1991 to 2020?
It is the most recent of the four climate periods shown on each Met Office station page, alongside 1981 to 2010, 1971 to 2000 and 1961 to 1990. Older periods are available for comparison on the same pages.
Can a dry region still have a drainage problem?
Yes. The Met Office holds its 60-minute rainfall record at Maidenhead in Berkshire, and short heavy downpours overload outlets wherever they fall. Roof drainage is designed for storm intensity, not for the annual total.
Does rain stop a re-roof from going ahead?
It can pause work at height. Employers must ensure work at height is carried out only when weather does not jeopardise safety. A method statement and a plan for keeping the open roof weathertight are the usual way to manage this.