| Lligwy Beach | Anglesey | Irish Sea | 15.2°C(59.4°F) | July, August, September, October | Live SST → |
| Loe Bar | Cornwall | Celtic Sea | 15.8°C(60.4°F) | July, August, September, October | Live SST → |
| Long Bay Beach | United Kingdom | Sargasso Sea | 27.6°C(81.7°F) | June, July, August, September, October | Live SST → |
| Long Sands | United Kingdom | Celtic Sea | 16.6°C(61.9°F) | July, August, September, October | Live SST → |
| Longniddry Bents | East Lothian | Inner Seas off the West Coast of Scotland | 13.5°C(56.3°F) | June, July, August, September | Live SST → |
| Lossit | Argyll and Bute | Inner Seas off the West Coast of Scotland | 14.2°C(57.6°F) | July, August, September, October | Live SST → |
| Lunan Bay | Angus | Sea of the Hebrides | 13.2°C(55.8°F) | July, August, September, October | Live SST → |
| Lund Beach | Shetland Islands | Rogaland County | 12.3°C(54.1°F) | July, August, September, October | Live SST → |
| Lusty Glaze Beach | Cornwall | Celtic Sea | 15.9°C(60.6°F) | July, August, September, October | Live SST → |
| Mackerel Cove | Cornwall | Celtic Sea | 16.1°C(61°F) | July, August, September, October | Live SST → |
| Mae Sand | Orkney | Sea of the Hebrides | 12.9°C(55.2°F) | July, August, September, October | Live SST → |
| Maidencombe Beach | Torbay | Celtic Sea | 16.8°C(62.2°F) | July, August, September, October | Live SST → |
| Man O' War Cove | Dorset | Celtic Sea | 17.2°C(63°F) | July, August, September, October | Live SST → |
| Manorbier Beach | Pembrokeshire | Celtic Sea | 16.5°C(61.7°F) | July, August, September, October | Live SST → |
| Mansands | United Kingdom | Celtic Sea | 16.6°C(61.9°F) | July, August, September, October | Live SST → |
| Margate Main Sands | Kent | Irish Sea | 17.5°C(63.5°F) | July, August, September, October | Live SST → |
| Marloes Sands | United Kingdom | Celtic Sea | 16.3°C(61.3°F) | July, August, September, October | Live SST → |
| Marske Sands | Redcar and Cleveland | North Sea | 13.9°C(57°F) | June, July, August, September | Live SST → |
| Meal Beach | Shetland Islands | Rogaland County | 12.2°C(54°F) | July, August, September, October | Live SST → |
| Middleton Beach | Hartlepool | North Sea | 13.9°C(57°F) | June, July, August, September | Live SST → |
| Mill Bay | Devon | Celtic Sea | 16.1°C(61°F) | July, August, September, October | Live SST → |
| Mill Sand | Orkney | Sea of the Hebrides | 13°C(55.4°F) | July, August, September, October | Live SST → |
| Mill Shore | Aberdeenshire | Sea of the Hebrides | 13.1°C(55.6°F) | July, August, September, October | Live SST → |
| Monmouth Beach | Devon | Celtic Sea | 17°C(62.6°F) | July, August, September, October | Live SST → |
| Morfa Dyffryn | Gwynedd | Irish Sea | 16.4°C(61.5°F) | June, July, August, September | Live SST → |
| Morning Beach | United Kingdom | Sargasso Sea | 27.6°C(81.7°F) | June, July, August, September, October | Live SST → |
| Mothecombe Beach | Devon | Celtic Sea | 16.1°C(61°F) | July, August, September, October | Live SST → |
| Mother Ivy's Bay | Cornwall | Celtic Sea | 16.1°C(61°F) | July, August, September, October | Live SST → |
| Mouisonniere | United Kingdom | Celtic Sea | 17.3°C(63.1°F) | July, August, September, October | Live SST → |
| Mouth Mill Beach (Pebble) | Devon | Celtic Sea | 16.8°C(62.2°F) | July, August, September, October | Live SST → |
| Mouthwell Beach | Devon | Celtic Sea | 16.1°C(61°F) | July, August, September, October | Live SST → |
| Nanjizal or Mill Bay | Cornwall | Celtic Sea | 15.8°C(60.4°F) | July, August, September, October | Live SST → |
| New Aberdour Beach | Aberdeenshire | Sea of the Hebrides | 13°C(55.4°F) | July, August, September, October | Live SST → |
| New Quay Beach | Ceredigion | Irish Sea | 16.1°C(61°F) | July, August, September, October | Live SST → |
| Newbiggin Beach | Northumberland | North Sea | 13.6°C(56.5°F) | June, July, August, September | Live SST → |
| Newquay (Fistral Beach) | Cornwall | Atlantic Ocean | 16.4°C(61.5°F) | Jul, Aug, Sep | Live SST → |
| Nicholaston Beach | Swansea | Irish Sea | 16.8°C(62.2°F) | July, August, September, October | Live SST → |
| North Beach | Ceredigion | Irish Sea | 16.6°C(61.9°F) | June, July, August, September | Live SST → |
| North Beach | Northumberland | North Sea | 13.6°C(56.5°F) | June, July, August, September | Live SST → |
| North Sands | Devon | Celtic Sea | 16.1°C(61°F) | July, August, September, October | Live SST → |
| North Sands | East Riding of Yorkshire | North Sea | 14°C(57.2°F) | July, August, September, October | Live SST → |
| North Sands | Hartlepool | North Sea | 13.9°C(57°F) | June, July, August, September | Live SST → |
| North Shore Beach | Conwy | Irish Sea | 15.8°C(60.4°F) | July, August, September, October | Live SST → |
| Northam Beach | Devon | Celtic Sea | 16.8°C(62.2°F) | July, August, September, October | Live SST → |
| Oddicombe Beach | Torbay | Celtic Sea | 16.6°C(61.9°F) | July, August, September, October | Live SST → |
| Old Town Beach | Isles of Scilly | Celtic Sea | 16.2°C(61.2°F) | June, July, August, September | Live SST → |
| Oldshoremore Beach | Highland | Sea of the Hebrides | 13.3°C(55.9°F) | July, August, September, October | Live SST → |
| Ostel Bay beach | Argyll and Bute | Inner Seas off the West Coast of Scotland | 13.9°C(57°F) | July, August, September, October | Live SST → |
| Parsons Bay Beach | United Kingdom | Sargasso Sea | 27.6°C(81.7°F) | June, July, August, September, October | Live SST → |
| Passage Cove (sand & shingle) tidal area | Cornwall | Celtic Sea | 15.9°C(60.6°F) | July, August, September, October | Live SST → |