Map of Lac Jally with depth contours

Lac Jally

46.7675° N, 70.272° W

Depth contours from the 2012 government survey. Not for navigation.

Download the depth map (SVG)

Lac Jally is 10.6 m deep at its deepest point, shallower than 72% of the 1,506 surveyed lakes in Quebec. It covers 0.25 km² and lies 4.9 km northeast of Saint-Paul-Est.

Maximum depth
10.6 msurveyed 2012
shallower than 72% of the 1,506 surveyed lakes in Quebec
Area
0.25 km²
smaller than 58% of the 29,407 lakes in Quebec
Shoreline
2.7 km
shorter than 67% of the 29,407 lakes in Quebec
Water clarity
2.7 mSecchi depth, 2025
less clear than 74% of the 805 monitored lakes in Quebec
Elevation
451 m

Today on the water

7.8 °C

Wind SSW 18 km/h

Observed at Montmagny, as of 8:00 a.m. EDT

calm Estimated waves, next 12 hours: up to 0.1 m. Around 9 a.m., wind from the southwest: the southwest shore is sheltered, waves build toward the northeast shore.

Hourly forecast, next 24 hours
Time9 a.m.12 p.m.3 p.m.6 p.m.9 p.m.12 a.m.3 a.m.6 a.m.
Wind km/hSW 20SW 20SW 20SW 20SW 20SW 20SW 20W 20
Gusts km/h40404040404040
Waves (est.) m0.10.10.10.1
Temp. °C91011119886
Precip. %30303000000

Today: A mix of sun and cloud with 30 percent chance of showers. Wind southwest 20 km/h gusting to 40. High 12. UV index 3 or moderate.

Weather: Montmagny (local forecast), as of 8:03 a.m. EDT

Sun and moon

Civil dawn
6:20 a.m.
Sunrise
6:50 a.m.
Sunset
6:05 p.m.
Civil dusk
6:35 p.m.
Moonrise
5:40 a.m.
Moonset
5:23 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

47% of Lac Jally is deeper than 5 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 2012 records a maximum depth of 10.6 m, drawn from 9 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 Depths are from government surveys and may be outdated.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 22 years between 2004 and 2025; the latest annual mean is 2.7 m.

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