Map of Long Lake with depth contours

Long Lake

44.6876° N, 78.1806° W

Depth contours from the 1983 government survey. Not for navigation.

Download the depth map (SVG)

Long Lake is 20 m deep at its deepest point, deeper than 60% of the 2,688 surveyed lakes in Ontario. It covers 1 km² and lies 8.4 km southwest of Apsley.

Government surveys have recorded 3 fish species here: lake trout, white sucker and brown bullhead.

Maximum depth
20 msurveyed 1983
deeper than 60% of the 2,688 surveyed lakes in Ontario
Area
1 km²
larger than 67% of the 18,731 lakes in Ontario
Shoreline
14.9 km
longer than 83% of the 18,731 lakes in Ontario
Water clarity
4.5 mSecchi depth, 2025
clearer than 71% of the 1,251 monitored lakes in Ontario
Fish species
3
fewer than 55% of the 2,454 surveyed lakes in Ontario
Elevation
290 m

Today on the water

4.2 °C

Wind NW 2 km/h

Observed at Apsley, as of 7:00 a.m. EDT

choppy Estimated waves, next 12 hours: up to 0.2 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
Time8 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/hW 15W 15NW 30NW 30NW 15var. 5var. 5var. 5
Gusts km/h5050
Waves (est.) m0.10.10.20.2
Temp. °C61013148410
Precip. %404020200000

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 14. UV index 4 or moderate.

Weather: Apsley (local forecast), as of 7:02 a.m. EDT

Sun and moon

Civil dawn
6:51 a.m.
Sunrise
7:20 a.m.
Sunset
6:38 p.m.
Civil dusk
7:07 p.m.
Moonrise
6:12 a.m.
Moonset
5:57 p.m.
Moon
Waning crescent, 1% lit

Air Quality Health Index

1 low risk

Peterborough, as of 6:00 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.

Depth

40% of Long Lake 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 1983 records a maximum depth of 20 m, drawn from 48 depth contours.

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 Depths are from government surveys and may be outdated.

Fish

Sport fish by the share of the 4 government surveys (2015–2015) that recorded them.

  • Lake Trout4 of 4
Other species (2)
  • White Sucker 3
  • Brown Bullhead 1

Numbers are the surveys that recorded each species.

Eating your catch

The provincial guide to eating fish (2026) sets limits for 1 species from Long Lake. Maximum meals per month:

SpeciesLengthGeneral populationSensitive population*Contaminant
Lake Trout45-50 cm124Mercury, PCB

* 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 15. Check seasons and limits before you fish.

Water

Clarity was measured with a Secchi disk in 20 years between 2001 and 2025; the latest annual mean is 4.5 m.

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

Getting on the water

1 listed boat launch. marks launches on the map.