Which is the rainiest city in the UK? Posted on 29 Jul 19:52 , 0 comments

So, we had some er... feedback from our last post regarding rainwater harvesting in the North West, but as awesome as the analysis was it didn't answer the question on everyone's lips:

Which is the rainiest city in the UK, is it Manchester? 

So back to the drawing board it seems. This actually would be straightforward,  but the wording "rainiest" is not entirely helpful.

Do we mean in which city is the most precipitation recorded ? Or in which city is rainfall most frequent? Or a mixture of the two? 

Again we took a look at the information out there and there are a number of articles by tabloids and broadsheets all published in October 2014. The articles appear to focus on total recorded rainfall (mm) as a measure of "rainyness" although the the MEN does include total number of rain days.  

We decided to use the Met Office data to obtain rainfall statistics for each city to understand where they ranked against each other. 

In the process we learnt (Wiki Alert!) that there are currently a total of 69 such cities in the United Kingdom : 51 in England, 7 in Scotland, 6 in Wales, and 5 in Northern Ireland. We've tried to include most UK cities and apologise in advance if your city is not on the list! Please don't be offended!

We decided to introduce a new measure.. wait for it the "freeflush factor" - yes! A unitless metric for the measure of "rainyness". This is simply a product of total rainfall and rain days normalised to the median (Dundee) which should provide a measure of how "rainy" a place is! Greater than 1 represents being rainier than the median whilst less than 1 less rainy -simplez! 

The table below can be sorted by total rainfall, days of rainfall or the freeflush factor!


City Rainfall(mm) Days of rainfall >1 mm freeflush factor f3
Glasgow 1124 170 2.14
St David 1138 151 1.92
Cardiff 1152 149 1.91
Newry 1019 167 1.89
Bangor 1100 151 1.85
Truro 1061 151 1.79
Preston 1034 153 1.77
Bradford 1024 152 1.74
Leeds 1024 152 1.74
Swansea 999 148 1.65
Belfast 944 156 1.64
Plymouth 1007 142 1.60
Lisburn 902 155 1.56
Newport 910 147 1.49
Manchester 867 152 1.47
Salford 867 152 1.47
Gloucester 843 146 1.37
Liverpool 837 144 1.35
St Asaph 814 146 1.32
Stoke on Trent 806 144 1.29
Aberdeen 815 139 1.26
Sheffield 835 132 1.23
Stirling 748 146 1.22
Perth 811 134 1.21
Bath 814 132 1.19
Birmingham 805 131 1.18
Inverness 733 143 1.17
Bristol 802 126 1.13
Chester 726 136 1.10
Exeter 785 121 1.06
Salisbury 749 122 1.02
Dundee 722 124 1.00
Southampton 779 115 1.00
Derby 709 124 0.98
Nottingham 709 124 0.98
Edinburgh 704 124 0.98
Winchester 747 116 0.97
Wells 709 122 0.97
Coventry 700 124 0.96
Lichfield 681 125 0.95
Wolverhamton 681 125 0.95
St Albans 712 119 0.94
Kingston upon Hull 680 123 0.93
Portsmouth 727 115 0.93
Norwich 674 123 0.92
Leicester 675 121 0.91
Durham 651 122 0.89
Hereford 665 115 0.85
Oxford 660 116 0.85
Ripon 643 118 0.85
York 626 117 0.82
Canterbury 646 110 0.79
Lincoln 615 115 0.79
Worcester 606 114 0.77
Wakefield 603 114 0.77
Peterborough 609 113 0.77
Newcastle upon Tyne 597 110 0.73
Sunderland 597 110 0.73
Chelmsford 592 108 0.71
Derry 571 109 0.69
Ely 574 108 0.69
Cambridge 568 108 0.68
London 557 109 0.68

 

It turns out Manchester is not the rainiest city! In fact it's 15th or 8th depending on which measure is used. 

Of the major cities Glasgow, Cardiff and Leeds all sit above Manchester in "rainyness". Glasgow appears to be the UK's rainest city since it appears 1st in two of the three measures considered (days of rainfall and freeflush factor). 

London and Cambridge appear to be the least rainiest cities.

So there you have it, based on the Met Office data and this analysis considering both magnitude and frequency of rainfall Glasgow is the UK's rainiest city and Manchester is not! 

Regardless of whether you're in a wet or dry city there's always benefits to rainwater harvesting, check out some of our products here.

If you have any questions, comments or suggestions for future posts please leave a note below or contact us.