Lac Saint-Mathieu
48.1537° N, 69.0224° W
Depth contours from the 1969 government survey. Not for navigation.
Download the depth map (SVG)Lac Saint-Mathieu, Quebec. 48.1537° N, 69.0224° W
Maximum depth 19.6 m (1969 survey). Scale bar on the map.
Not for navigation. Depths are from government surveys and may be outdated.
borealbound.ca/lakes/qc/lac-saint-mathieu/, 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.
- 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).
Lac Saint-Mathieu is 19.6 m deep at its deepest point, deeper than 61% of the 1,506 surveyed lakes in Quebec. It covers 5.69 km² and lies beside Saint-Mathieu.
- Maximum depth
- 19.6 msurveyed 1969
- deeper than 61% of the 1,506 surveyed lakes in Quebec
- Area
- 5.69 km²
- larger than 92% of the 29,407 lakes in Quebec
- Shoreline
- 19.5 km
- longer than 88% of the 29,407 lakes in Quebec
- Water clarity
- 1.8 mSecchi depth, 2025
- less clear than 89% of the 805 monitored lakes in Quebec
- Elevation
- 113 m
Today on the water
7.2 °C
Observed at Trois-Pistoles, as of 6:00 a.m. EDT
choppy Estimated waves, next 12 hours: up to 0.3 m. Around 7 a.m., wind from the southwest: the southwest shore is sheltered, waves build toward the northeast shore.
| Time | 7 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/h | SW 20 | W 20 | W 20 | W 20 | W 20 | W 20 | W 20 | W 20 |
| Gusts km/h | 40 | 40 | 40 | 40 | 40 | 40 | 40 | 40 |
| Waves (est.) m | 0.3 | 0.2 | 0.2 | 0.2 | ||||
| Temp. °C | 7 | 7 | 8 | 7 | 7 | 6 | 5 | 5 |
| Precip. % | 0 | 30 | 30 | 30 | 0 | 0 | 0 | 0 |
Today: A mix of sun and cloud. 30 percent chance of showers late this morning and this afternoon. Wind west 20 km/h gusting to 40. Temperature steady near 8. UV index 3 or moderate.
Weather: Trois-Pistoles (local forecast), as of 6:00 a.m. EDT
Sun and moon
- Civil dawn
- 6:15 a.m.
- Sunrise
- 6:46 a.m.
- Sunset
- 5:58 p.m.
- Civil dusk
- 6:30 p.m.
- Moonrise
- 5:35 a.m.
- Moonset
- 5:16 p.m.
- Moon
- Waning crescent, 1% lit
Depth
33% of Lac Saint-Mathieu 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 1969 records a maximum depth of 19.6 m, drawn from 19 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: eutrophic.
Clarity was measured with a Secchi disk in 14 years between 2011 and 2025; the latest annual mean is 1.8 m.