Lac Marois
45.8516° N, 74.1313° W
Depth contours from the 2010 government survey. Not for navigation.
Download the depth map (SVG)Lac Marois, Quebec. 45.8516° N, 74.1313° W
Maximum depth 23.6 m (2010 survey). Scale bar on the map.
Not for navigation. Depths are from government surveys and may be outdated.
borealbound.ca/lakes/qc/lac-marois/, compiled October 9, 2026
- Canadian Geographical Names Database, Natural Resources Canada. Contains information licensed under the Open Government Licence – Canada.
- HydroLAKES v1.0, Messager et al. 2016 / WWF HydroSHEDS. Licensed under CC BY 4.0.
- Census boundaries and population, 2021, Statistics Canada. Adapted from Statistics Canada. This does not constitute an endorsement by Statistics Canada.
- Géobase des bathymétries de lac du Québec (GBLQ), Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs. Licensed under CC BY 4.0. Source: Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs (MELCCFP), Données Québec.
- États trophiques des lacs (RSVL), Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs. Licensed under CC BY 4.0. Source: Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs (MELCCFP), Données Québec.
- Real-time hydrometric data, Environment and Climate Change Canada. Contains data from Environment and Climate Change Canada (ECCC Data Servers End-use Licence).
- National Water Data Archive (HYDAT) daily means, Environment and Climate Change Canada. Contains data from Environment and Climate Change Canada (ECCC Data Servers End-use Licence).
- City page weather forecasts and alerts, Environment and Climate Change Canada. Contains data from Environment and Climate Change Canada (ECCC Data Servers End-use Licence).
- Air Quality Health Index observations and forecasts, Environment and Climate Change Canada. Contains data from Environment and Climate Change Canada (ECCC Data Servers End-use Licence).
- Photographs, Wikimedia Commons contributors. Each photo carries its own licence (CC0, public domain, CC BY or CC BY-SA), credited where shown.
Lac Marois is 23.6 m deep at its deepest point, deeper than 71% of the 1,506 surveyed lakes in Quebec. It covers 0.95 km² and lies beside Lac-Saint-Amour.
- Maximum depth
- 23.6 msurveyed 2010
- deeper than 71% of the 1,506 surveyed lakes in Quebec
- Area
- 0.95 km²
- larger than 73% of the 29,407 lakes in Quebec
- Shoreline
- 5.9 km
- longer than 66% of the 29,407 lakes in Quebec
- Water clarity
- 5.1 mSecchi depth, 2025
- clearer than 73% of the 805 monitored lakes in Quebec
- Elevation
- 289 m
Today on the water
YELLOW ADVISORY - FROST · issued 4:39 a.m. EDT
Temperatures will drop to near the freezing mark overnight tonight. Take preventative measures to protect cold-sensitive plants, trees, and crops. Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to QCstorm@ec.gc.ca or post reports on social media using #QCStorm.
Official alert on weather.gc.ca · expires 11:29 p.m. EDT
6 °C
Observed at Saint-Jérôme, as of 7:00 a.m. EDT
calm Estimated waves, next 12 hours: up to 0.1 m. Around 8 a.m., wind from the west: the west shore is sheltered, waves build toward the east shore.
| Time | 8 a.m. | 11 a.m. | 2 p.m. | 5 p.m. | 8 p.m. | 11 p.m. | 2 a.m. | 5 a.m. |
|---|---|---|---|---|---|---|---|---|
| Wind km/h | W 10 | W 20 | W 20 | W 20 | W 10 | W 10 | W 10 | NW 10 |
| Gusts km/h | 40 | 40 | 40 | |||||
| Waves (est.) m | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | |||
| Temp. °C | 10 | 11 | 14 | 11 | 8 | 6 | 3 | 2 |
| Precip. % | 40 | 40 | 40 | 40 | 0 | 0 | 0 | 0 |
Today: A mix of sun and cloud with 40 percent chance of showers. Risk of a thunderstorm this afternoon. Wind becoming west 20 km/h gusting to 40 this morning. High 14. UV index 3 or moderate.
Weather: Saint-Jérôme (local forecast), as of 7:05 a.m. EDT
Sun and moon
- Civil dawn
- 6:35 a.m.
- Sunrise
- 7:05 a.m.
- Sunset
- 6:21 p.m.
- Civil dusk
- 6:51 p.m.
- Moonrise
- 5:56 a.m.
- Moonset
- 5:39 p.m.
- Moon
- Waning crescent, 1% lit
Depth
38% of Lac Marois 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 2010 records a maximum depth of 23.6 m, drawn from 36 depth contours.
- Download the depth map (SVG)Printing this page gives the map on one sheet, with scale and sources.
- Official government depth map (PDF)
Not for navigation. Depths are from government surveys and may be outdated.
Water
Trophic status from the latest monitoring: oligotrophic.
Clarity was measured with a Secchi disk in 18 years between 2008 and 2025; the latest annual mean is 5.1 m.