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Map of Thaddeus Lake

Thaddeus Lake

50.1746° N, 92.8925° W

Shoreline and neighbouring water from open government data.

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Thaddeus Lake, Ontario. 50.1746° N, 92.8925° W

Not for navigation. Depths are from government surveys and may be outdated.

borealbound.ca/lakes/on/thaddeus-lake/, 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.
  • Aquatic Resource Area survey points, Ontario Ministry of Natural Resources. Contains information licensed under the Open Government Licence – Ontario.
  • Fishing access points, Ontario Ministry of Natural Resources. Contains information licensed under the Open Government Licence – Ontario.
  • Fisheries Management Zones, Ontario Ministry of Natural Resources. Contains information licensed under the Open Government Licence – Ontario.
  • Lake Partner Program, Ontario Ministry of the Environment, Conservation and Parks. Contains information licensed under the Open Government Licence – Ontario.
  • 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).
  • Guide to Eating Ontario Fish: Advisory Database, Ontario Ministry of the Environment, Conservation and Parks. Contains information licensed under the Open Government Licence – Ontario.

Thaddeus Lake covers 15.7 km², making it larger than 97% of the 18,731 lakes in Ontario. It lies 15 km north of Amesdale.

Government surveys have recorded 9 fish species here, including walleye, yellow perch and cisco.

Area
15.7 km²
larger than 97% of the 18,731 lakes in Ontario
Shoreline
21.6 km
longer than 89% of the 18,731 lakes in Ontario
Water clarity
3.2 mSecchi depth, 2018
less clear than 58% of the 1,251 monitored lakes in Ontario
Fish species
9
more than 69% of the 2,454 surveyed lakes in Ontario
Elevation
376 m

Today on the water

4 °C

Mainly ClearWind S 13 km/h

Observed at Dryden, as of 6:00 a.m. CDT

choppy Estimated waves, next 12 hours: up to 0.3 m. Around 4 p.m., wind from the southeast: the southeast shore is sheltered, waves build toward the northwest shore.

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/hS 10S 15E 10SE 20SE 20SE 20SE 20SE 20
Gusts km/h4040404040
Waves (est.) m0.20.20.10.30.3
Temp. °C57111513111110
Precip. %2020404010101010

Today: A mix of sun and cloud. Becoming cloudy near noon with 40 percent chance of rain this afternoon. Wind becoming southeast 20 km/h gusting to 40 late this afternoon. High 15. UV index 2 or low.

Weather: Dryden (local forecast), as of 6:01 a.m. CDT

Sun and moon

Civil dawn
6:51 a.m.
Sunrise
7:24 a.m.
Sunset
6:32 p.m.
Civil dusk
7:04 p.m.
Moonrise
6:17 a.m.
Moonset
5:51 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.

Fish

Sport fish by the share of the 14 government surveys (2009–2009) that recorded them.

  • Walleye14 of 14
  • Yellow Perch13 of 14
  • Cisco11 of 14
  • Northern Pike10 of 14
  • Muskellunge3 of 14
  • Smallmouth Bass2 of 14
Forage fish and other species (3)

Forage fish

  • Spottail Shiner 6
  • Trout-Perch 5

Other

  • White Sucker 8

Numbers are the surveys that recorded each species.

Eating your catch

The provincial guide to eating fish (2026) sets limits for 4 species from Thaddeus Lake. Maximum meals per month:

SpeciesLengthGeneral populationSensitive population*Contaminant
Muskellunge>75 cm4Do not eatMercury
Northern Pike55-60 cm124Mercury
Smallmouth Bass35-40 cm164Mercury
Walleye40-45 cm84Mercury

* As defined in the guide, including children and people who are or may become pregnant. Limits are for the length the guide lists most often; they change with the size of the fish. Read the official guide

Fishing regulations: Fisheries Management Zone 4. Check seasons and limits before you fish.

Water

Total phosphorus (µg/L)

Getting on the water

1 listed boat launch. marks launches on the map.