Map of Lac François with depth contours

Lac François

46.4973° N, 75.3054° W

Depth contours from the 2014 government survey. Not for navigation.

Download the depth map (SVG)

Lac François is 27.4 m deep at its deepest point, deeper than 78% of the 1,506 surveyed lakes in Quebec. It covers 1.83 km² and lies beside Lac-François.

Maximum depth
27.4 msurveyed 2014
deeper than 78% of the 1,506 surveyed lakes in Quebec
Area
1.83 km²
larger than 82% of the 29,407 lakes in Quebec
Shoreline
13.9 km
longer than 83% of the 29,407 lakes in Quebec
Water clarity
3.1 mSecchi depth, 2025
less clear than 65% of the 805 monitored lakes in Quebec
Elevation
246 m

Today on the water

5.8 °C

Wind WNW 5 km/h

Observed at Mont-Laurier, as of 6:00 a.m. EDT

choppy Estimated waves, next 12 hours: up to 0.2 m. Around 12 p.m., wind from the northwest: the northwest shore is sheltered, waves build toward the southeast shore.

Hourly forecast, next 24 hours
Time7 a.m.10 a.m.1 p.m.4 p.m.7 p.m.10 p.m.1 a.m.4 a.m.
Wind km/hW 10W 10NW 20NW 20NW 15NW 10var. 5var. 5
Waves (est.) m0.10.10.20.2
Temp. °C5798531-1
Precip. %303030300000

Today: A mix of sun and cloud with 30 percent chance of showers. Wind becoming northwest 20 km/h near noon. High 9. UV index 3 or moderate.

Weather: Mont-Laurier (local forecast), as of 6:02 a.m. EDT

Sun and moon

Civil dawn
6:40 a.m.
Sunrise
7:10 a.m.
Sunset
6:25 p.m.
Civil dusk
6:55 p.m.
Moonrise
6:01 a.m.
Moonset
5:43 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

25% of Lac François is shallower than 3 m, and 30% is deeper than 10 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 2014 records a maximum depth of 27.4 m, drawn from 54 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 Depths are from government surveys and may be outdated.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 18 years between 2005 and 2025; the latest annual mean is 3.1 m.

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