Map of Seymour Lake

Seymour Lake

44.3849° N, 77.8098° W

Shoreline and neighbouring water from open government data.

Download the map (SVG)

Seymour Lake covers 7.3 km², making it larger than 94% of the 18,731 lakes in Ontario. It lies beside Trent River.

Area
7.3 km²
larger than 94% of the 18,731 lakes in Ontario
Shoreline
52.6 km
longer than 96% of the 18,731 lakes in Ontario
Water clarity
1.7 mSecchi depth, 2025
less clear than 91% of the 1,251 monitored lakes in Ontario
Elevation
182 m

Today on the water

8.3 °C

Partly CloudyWind WSW 13 km/h

Observed at Stirling, as of 5:00 a.m. EDT

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

Hourly forecast, next 24 hours
Time6 a.m.9 a.m.12 p.m.3 p.m.6 p.m.9 p.m.12 a.m.3 a.m.
Wind km/hW 15W 15NW 30NW 30NW 15var. 5var. 5var. 5
Gusts km/h5050
Waves (est.) m0.20.20.30.30.2
Temp. °C68121413952
Precip. %4040402020000

Today: A mix of sun and cloud. 40 percent chance of showers this morning and early this afternoon. Wind becoming northwest 30 km/h gusting to 50 near noon. High 15. UV index 4 or moderate.

Weather: Stirling (local forecast), as of 5:02 a.m. EDT

Sun and moon

Civil dawn
6:49 a.m.
Sunrise
7:18 a.m.
Sunset
6:37 p.m.
Civil dusk
7:06 p.m.
Moonrise
6:10 a.m.
Moonset
5:55 p.m.
Moon
Waning crescent, 1% lit

Air Quality Health Index

2 low risk

Belleville, as of 4:00 a.m. EDT

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.

Water

Clarity was measured with a Secchi disk in 5 years between 2021 and 2025; the latest annual mean is 1.7 m.

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

Getting on the water

2 listed boat launches; 1 with parking listed. marks launches on the map.

East shore

West shore