Hardest and softest tap water in the United Kingdom
All 471 cities in the United Kingdom with published data, ranked by total hardness. The national median is 185 mg/L.
UK suppliers report mg/L CaCO₃ and often Clark degrees (1 °Clark = 14.25 mg/L).
25 cities with the hardest water
| # | mg/L | mg/L | ||
|---|---|---|---|---|
| 1 | Sherborne · Dorset | 372 | 372 | very hard |
| 2 | Holt · Wiltshire | 371 | 371 | very hard |
| 3 | Cottingham · East Riding of Yorkshire | 371 | 371 | very hard |
| 4 | Seend · Wiltshire | 367 | 367 | very hard |
| 5 | Milborne Port · South Somerset | 365 | 365 | very hard |
| 6 | Westwood · Wiltshire | 365 | 365 | very hard |
| 7 | Kingston upon Hull · East Riding of Yorkshire; Kingston upon Hull | 362 | 362 | very hard |
| 8 | Bradford on Avon · Wiltshire | 360 | 360 | very hard |
| 9 | Calne · Wiltshire | 358 | 358 | very hard |
| 10 | Beverley · East Riding of Yorkshire | 355 | 355 | very hard |
| 11 | Devizes · Wiltshire | 354 | 354 | very hard |
| 12 | Sandwich · Dover | 352 | 352 | very hard |
| 13 | Melksham · Wiltshire | 345 | 345 | very hard |
| 14 | Chippenham · Wiltshire | 342 | 342 | very hard |
| 15 | Romsey · Test Valley | 341 | 341 | very hard |
| 16 | Overton · Basingstoke and Deane | 337 | 337 | very hard |
| 17 | Potterne · Wiltshire | 334 | 334 | very hard |
| 18 | Broadstairs · Thanet | 332 | 332 | very hard |
| 19 | Margate · Thanet | 332 | 332 | very hard |
| 20 | Corsham · Wiltshire | 330 | 330 | very hard |
| 21 | Whitley · Wiltshire | 330 | 330 | very hard |
| 22 | Ramsgate · Thanet | 330 | 330 | very hard |
| 23 | Neston · Wiltshire | 329 | 329 | very hard |
| 24 | Box · Wiltshire | 328 | 328 | very hard |
| 25 | Malmesbury · Wiltshire | 328 | 328 | very hard |
25 cities with the softest water
| # | mg/L | mg/L | ||
|---|---|---|---|---|
| 1 | Tarbert · Scotland | 8 | 8 | soft |
| 2 | Stornoway · Scotland | 10 | 10 | soft |
| 3 | Ardrishaig · Scotland | 10 | 10 | soft |
| 4 | Glasgow · Scotland | 16 | 16 | soft |
| 5 | Milngavie · Scotland | 16 | 16 | soft |
| 6 | Barnoldswick · Pendle | 17 | 17 | soft |
| 7 | Skipton · Craven | 18 | 18 | soft |
| 8 | Low Bradley · Craven | 19 | 19 | soft |
| 9 | Benbecula · Scotland | 20 | 20 | soft |
| 10 | Barra · Scotland | 21 | 21 | soft |
| 11 | Ullapool · Scotland | 21 | 21 | soft |
| 12 | Horbury · Wakefield | 22 | 22 | soft |
| 13 | Newtownards · Northern Ireland | 23 | 23 | soft |
| 14 | Saintfield · Northern Ireland | 23 | 23 | soft |
| 15 | Killyleagh · Northern Ireland | 23 | 23 | soft |
| 16 | Hillsborough · Northern Ireland | 23 | 23 | soft |
| 17 | Crossgar · Northern Ireland | 23 | 23 | soft |
| 18 | Ballynahinch · Northern Ireland | 23 | 23 | soft |
| 19 | Ballygowan · Northern Ireland | 23 | 23 | soft |
| 20 | Annahilt · Northern Ireland | 23 | 23 | soft |
| 21 | Carryduff · Northern Ireland | 23 | 23 | soft |
| 22 | Bangor · Northern Ireland | 23 | 23 | soft |
| 23 | Millisle · Northern Ireland | 23 | 23 | soft |
| 24 | Donaghadee · Northern Ireland | 23 | 23 | soft |
| 25 | Comber · Northern Ireland | 23 | 23 | soft |