Map of Lac Mégantic with depth contours

Lac Mégantic

45.5602° N, 70.9048° W

Depth contours from the 2013 government survey. Not for navigation.

Download the depth map (SVG)

Lac Mégantic is 75.4 m deep at its deepest point, deeper than 98% of the 1,506 surveyed lakes in Quebec. It covers 28.7 km² and lies beside Lac-Mégantic.

Maximum depth
75.4 msurveyed 2013
deeper than 98% of the 1,506 surveyed lakes in Quebec
Area
28.7 km²
larger than 98% of the 29,407 lakes in Quebec
Shoreline
80.4 km
longer than 97% of the 29,407 lakes in Quebec
Water clarity
3.7 mSecchi depth, 2025
less clear than 52% of the 805 monitored lakes in Quebec
Elevation
392 m

Today on the water

6 °C

Wind SW 13 km/h, gusts 27

Observed at Lac-Mégantic, as of 1:00 a.m. EDT

choppy Estimated waves, next 12 hours: up to 0.3 m. Wind from the southwest: the southwest shore is sheltered, waves build toward the northeast shore.

Hourly forecast, next 24 hours
Time2 a.m.5 a.m.8 a.m.11 a.m.2 p.m.5 p.m.8 p.m.11 p.m.
Wind km/hW 10W 10W 10W 20W 20W 20W 20W 15
Gusts404040
Waves (est.) m0.10.10.10.30.3
Temp. °C99810111065
Precip. %606040404040400

Tonight: Mainly cloudy with 60 percent chance of showers. Risk of a thunderstorm this evening. Wind west 20 km/h gusting to 40 becoming light this evening. Low 8.

Weather: Lac-Mégantic (local forecast), as of 1:04 a.m. EDT

Sun and moon

Civil dawn
6:22 a.m.
Sunrise
6:52 a.m.
Sunset
6:08 p.m.
Civil dusk
6:38 p.m.
Moonrise
5:42 a.m.
Moonset
5:26 p.m.
Moon
Waning crescent, 1% lit

Data Source: Environment and Climate Change Canada. Local times.

How waves are estimated

Significant wave height from the forecast hourly wind and the open-water distance (fetch) upwind, using the SMB method (US Army Corps of Engineers Shore Protection Manual, 1984), rounded up to the next 0.1 m. It is not a measurement: gusts, leftover swell and shoals can make water rougher. Under 0.2 m: calm; 0.2–0.5 m: choppy; over 0.5 m: rough.

Depth

31% of Lac Mégantic is deeper than 30 m.

How to read it: the lake’s area is sorted from the shore to the deepest point. Where the curve is flat, large areas share one depth (flats and weed beds); where it drops, depth changes quickly (drop-offs).

The government depth survey from 2013 records a maximum depth of 75.4 m, drawn from 83 depth contours.

Not for navigation. Depths are from government surveys and may be outdated.

Water

Trophic status from the latest monitoring: mesotrophic.

Clarity was measured with a Secchi disk in 15 years between 2010 and 2025; the latest annual mean is 3.7 m.

Water clarity (Secchi depth, m)
Total phosphorus (µg/L)

Photos

Lac Mégantic - panoramio
Photo: pgmoisan, CC BY 3.0, via Wikimedia Commons
Lac Mégantic du mont Mégantic
Photo: Khayman, CC BY-SA 3.0, via Wikimedia Commons
Lac Mégantic vu du mont Mégantic02
Photo: Khayman, CC BY-SA 3.0, via Wikimedia Commons