Lac Mahon
45.688° N, 76.0113° W
Shoreline and neighbouring water from open government data.
Download the map (SVG)Lac Mahon, Quebec. 45.688° N, 76.0113° W
Not for navigation. Depths are from government surveys and may be outdated.
borealbound.ca/lakes/qc/lac-mahon/, 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.
- 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).
- 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).
Lac Mahon covers 1.21 km², making it larger than 77% of the 29,407 lakes in Quebec. It lies beside Rupert.
- Area
- 1.21 km²
- larger than 77% of the 29,407 lakes in Quebec
- Shoreline
- 5 km
- longer than 61% 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
- 157 m
Today on the water
5.7 °C
Observed at Chelsea, as of 3:00 a.m. EDT
choppy Estimated waves, next 12 hours: up to 0.2 m. Around 9 a.m., wind from the northwest: the northwest shore is sheltered, waves build toward the southeast shore.
| Time | 4 a.m. | 7 a.m. | 10 a.m. | 1 p.m. | 4 p.m. | 7 p.m. | 10 p.m. | 1 a.m. |
|---|---|---|---|---|---|---|---|---|
| Wind km/h | W 10 | NW 10 | NW 20 | NW 20 | NW 20 | NW 10 | var. 5 | var. 5 |
| Waves (est.) m | 0.1 | 0.1 | 0.2 | 0.2 | 0.2 | |||
| Temp. °C | 5 | 5 | 8 | 11 | 11 | 7 | 4 | 2 |
| Precip. % | 60 | 30 | 30 | 30 | 30 | 0 | 0 | 0 |
Tonight: Partly cloudy with 60 percent chance of showers. Wind west 20 km/h becoming light early this evening. Low plus 5.
Weather: Chelsea (local forecast), as of 3:01 a.m. EDT
Sun and moon
- Civil dawn
- 6:42 a.m.
- Sunrise
- 7:12 a.m.
- Sunset
- 6:29 p.m.
- Civil dusk
- 6:58 p.m.
- Moonrise
- 6:04 a.m.
- Moonset
- 5:47 p.m.
- Moon
- Waning crescent, 1% lit
Follow this lake by email: a weekly summary of conditions.
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 3.7 m.
Follow this lake
Every Friday by email: the Environment Canada forecast and any weather alerts in effect.