Maine has more than 6,000 lakes and ponds. That is a lot of water to sort through when all you want is a clean, beautiful place to swim on a hot July afternoon.
We have narrowed it down to 15 lakes that deliver on clarity, scenery, access, and overall swimming experience. Some are well-known destinations with sandy beaches and lifeguards. Others are quiet spots where you might have a granite ledge to yourself all day.
1. Sebago Lake
Location: Standish/Casco/Naples | Size: 28,771 acres | Max Depth: 316 ft
Sebago is the deepest and second-largest lake in Maine, and its water is so clean that it serves as Portland’s drinking supply without filtration. The visibility here is extraordinary. Sebago Lake State Park has two sand beaches, picnic areas, and lifeguards on duty in summer.
Swimming access: Sebago Lake State Park (day use fee $8/adult). The beach at the Casco side tends to be less crowded than the Naples side.
2. Moosehead Lake
Location: Greenville | Size: 74,890 acres | Max Depth: 246 ft
Maine’s largest lake sits in the heart of the North Woods with Mount Kineo rising dramatically from its center. The water is cold even in August, but on a hot day the mountain backdrop and sense of wildness make it unlike any other swim in the state.
Swimming access: Greenville town beach (free), or Lily Bay State Park ($8/adult) for more space and a sandy shoreline.
3. Rangeley Lake
Location: Rangeley | Size: 6,000 acres | Max Depth: 149 ft
Surrounded by mountains and dense forest, Rangeley Lake feels genuinely remote even though the town of Rangeley sits right on its shore. The water is clean and clear, and the Rangeley Lake State Park beach has a gentle sandy entry that is perfect for kids.
Swimming access: Rangeley Lake State Park ($8/adult) or the free town beach near the boat launch.
4. Echo Lake (Acadia National Park)
Location: Mount Desert Island | Size: 237 acres | Max Depth: 66 ft
Echo Lake is Acadia’s freshwater swimming spot, and it is warmer than the ocean beaches by a wide margin. A small sand beach with a lifeguard sits at the south end, with Beech Mountain and Acadia Mountain framing the view. This might be the most scenic lake swim in Maine.
Swimming access: Echo Lake Beach, Acadia National Park (park entrance pass required). Parking fills early, so arrive before 10 AM or take the Island Explorer shuttle.
5. Thompson Lake
Location: Oxford/Casco/Otisfield | Size: 4,400 acres | Max Depth: 118 ft
Thompson is one of the cleanest lakes in southern Maine, consistently ranked among the state’s clearest. The water has a slightly blue tint on sunny days, and the sandy bottom makes for comfortable wading. It is popular with locals but rarely feels overcrowded.
Swimming access: Several informal access points and camp beaches. The public boat launch in Oxford has a small swim area.
6. Long Lake
Location: Naples/Bridgton/Harrison | Size: 5,052 acres | Max Depth: 62 ft
Long Lake sits at the center of the Lakes Region, connected to Sebago by the Songo River. The Causeway Beach in Naples is the social hub, with the town’s shops and restaurants within walking distance. The water is warm by Maine standards and the sandy beach is expansive.
Swimming access: Naples Causeway Beach (free, public). Bridgton also has Highland Lake nearby for a quieter alternative.
7. Damariscotta Lake
Location: Jefferson/Nobleboro/Newcastle | Size: 4,381 acres | Max Depth: 114 ft
A Midcoast gem with excellent water clarity and a relatively undeveloped shoreline. Damariscotta Lake State Park has a shaded picnic area and a sand beach that slopes gently into the water. The lake warms up nicely by mid-July.
Swimming access: Damariscotta Lake State Park ($8/adult). It is rarely crowded, even on weekends.
8. Lake St. George
Location: Liberty | Size: 1,017 acres | Max Depth: 63 ft
Lake St. George State Park is one of the most underrated swimming spots in Maine. The beach is well-maintained with a roped swim area, picnic tables under tall pines, and warm water from late June on. The surrounding area feels unhurried and uncommercial.
Swimming access: Lake St. George State Park ($8/adult).
9. Branch Lake
Location: Ellsworth | Size: 2,987 acres | Max Depth: 123 ft
Branch Lake serves as Ellsworth’s drinking water supply, which means it is carefully protected and exceptionally clean. The town beach has a sandy shoreline and a dock for jumping. Being just 15 minutes from Acadia, it makes an excellent complement to a coastal trip.
Swimming access: Branch Lake Public Beach (free, Ellsworth residents and visitors welcome).
10. Great Pond (Belgrade Lakes)
Location: Belgrade/Rome | Size: 8,239 acres | Max Depth: 69 ft
The Belgrade Lakes chain has been a summer destination since the 1800s, and Great Pond is the largest of the group. The water is clean, warm, and surrounded by classic Maine lake cabins. The area inspired the movie “On Golden Pond” (though the film was shot in New Hampshire).
Swimming access: Belgrade town beach on West Road (free). Several rental camps also provide lake access.
11. Kezar Lake
Location: Lovell | Size: 2,525 acres | Max Depth: 154 ft
Kezar is consistently rated as one of the most beautiful lakes in Maine. Surrounded by the White Mountain foothills with minimal shoreline development, the water is deep, clear, and strikingly blue. The public beach at the north end has mountain views in every direction.
Swimming access: Kezar Lake public beach in Lovell (free, limited parking).
12. China Lake
Location: China/Vassalboro | Size: 3,845 acres | Max Depth: 85 ft
China Lake has made a strong recovery from water quality issues in the 1990s, and the swimming is once again excellent. The town beach in China village has a sandy bottom and a relaxed atmosphere. It warms up quickly in summer due to its relatively shallow average depth.
Swimming access: China Lake public beach (free).
13. Clearwater Lake
Location: Industry/Farmington | Size: 721 acres | Max Depth: 62 ft
The name says it all. Clearwater is a small, clean lake in Franklin County with a well-maintained town beach. The sandy bottom extends well out from shore, and the surrounding hills keep the wind down on most days. A peaceful, uncrowded swim spot.
Swimming access: Town beach off Clearwater Lake Road (free).
14. Lake Webb
Location: Weld | Size: 2,569 acres | Max Depth: 109 ft
Mount Blue State Park sits on the shore of Lake Webb and offers one of the best state park beaches in Maine. The sandy beach is large, the water is clean, and Tumbledown Mountain rises behind the far shore. It is a long drive from the coast, but the combination of lake swimming and mountain scenery is worth it.
Swimming access: Mount Blue State Park ($8/adult).
15. Megunticook Lake
Location: Camden/Lincolnville/Hope | Size: 1,274 acres | Max Depth: 63 ft
Camden is famous for its harbor, but Megunticook Lake, just inland, is where locals go to swim. Barrett Cove Memorial Park has a public beach with clear water and views of the surrounding hills. After your swim, you are a short drive from downtown Camden and the coast.
Swimming access: Barrett Cove Memorial Park, Lincolnville (free).
Tips for Lake Swimming in Maine
Water temperature: Most Maine lakes are comfortable for swimming from late June through early September. Deeper lakes like Sebago and Moosehead stay cold well into July. Shallower lakes warm up faster.
Leeches and loons: Leeches are uncommon in most of these lakes but not unheard of. If you are swimming from a rocky or weedy shore, check yourself afterward. Loons are common and protected. Give them space, especially during nesting season.
Leave no trace: Pack out everything you bring. Maine’s clean lakes stay clean because people respect them.
Algae blooms: Check the Maine DEP lake water quality reports before visiting, particularly in late summer. Blue-green algae blooms occasionally occur and can be harmful. If the water looks like spilled paint, stay out.