Open Water Data

Bigfork Community Dock - Flathead Lake

Bigfork, Montana, United States

  • Water Quality Status
    Passed tests Wed, Sep 3, 2025 at 4:33pm
  • Air Temperature
    -0.3°C / 31.5°F (air) Sun, Dec 4, 2022 at 9:15pm
  • Wind
    15.1 - 7.6km/h NNE 30° Sun, Dec 4, 2022 at 9:15pm
  • Clear
    Clear Sun, Dec 4, 2022 at 9:15pm
  • Precipitation
    0mm Sun, Dec 4, 2022 at 9:15pm
  • Air Visibility
    2km Sun, Dec 4, 2022 at 9:15pm
  • Humidity
    63% Sun, Dec 4, 2022 at 9:15pm

Flathead Lake in northwest Montana is the largest natural freshwater lake west of the Mississippi; slightly larger than Lake Tahoe at 27.3 mi. long, 15.5 mi. wide, and max depth of 370.7 ft.

The Bigfork Community Dock is in downtown Bigfork on the south side of Grand Dr, immediately to the west of the Swan River Inn. It offers public boat access to downtown Bigfork and swimming in Bigfork Harbor for pedestrians in town. There is a gravel parking lot to the north, across Grand Dr. There are no facilities at the dock, but the nearest public restrooms are around the corner to the south on Electric Avenue at the Bigfork Public Library.

As one of the cleanest in the world, Flathead Lake is perfect for OPEN WATER SWIMMING! No sharks, no jellyfish, and no lane lanes...just clear, clean, and crisp water!

Unless you like your water COLD, the effective swimming season is June through September. Average water temps in June are in the 60s, 70s in July and August, and then back down again in September.

Summer air temperatures average in the mid-70s to mid-80s.

Swim Guide shares the best information we have at the moment you ask for it. Always obey signs at the beach or advisories from official government agencies. Stay alert and check for other swimming hazards such as dangerous currents and tides. Please report your pollution concerns so Affiliates can help keep other beach-goers safe.

Beach conditions change constantly, and it is never wise to swim in open water up to 48-hours after a heavy rain. Please use caution!

The description above was copied from or heavily based on Swim Guide, with permission.

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