Loughborough Lake

Where Loughborough Lake is

Loughborough Lake lies in the County of Frontenac, within the Township of South Frontenac.

How deep is Loughborough Lake?

The deepest mapped contour on Loughborough Lake is 4.6 meters, and the water within that boundary descends even farther. Ontario’s bathymetry record holds 34 depth contours for Loughborough Lake.

See also Ontario's Largest and Deepest Lakes

Surveyed Depths

Ontario has surveyed the depths of several thousand of its lakes over more than half a century. Later surveys were conducted by boat with satellite positioning and produced hundreds of thousands of soundings per lake. Earlier surveys were charted by running transects across the water and drawing depth contours by hand.

Water quality

Ontario’s Lake Partner Program is a volunteer monitoring network. Participants collect water samples for phosphorus analysis and measure water clarity through the summer with a Secchi disk. Most sites are sampled for phosphorus once a year, in spring, and some several times a year between spring and fall. Phosphorus in many lakes rises through the summer, so the two kinds of average are measured on different bases.

Phosphorus is the nutrient that controls how much algae a lake can grow. A lake with little phosphorus stays clear and supports cold-water fish such as lake trout. As phosphorus rises, algae increase, the water clouds, and oxygen in the deep water falls as the algae decay. The province classifies each monitoring site by its average phosphorus:

• Oligotrophic, below 10 micrograms per litre: clear water and low algae.
• Mesotrophic, from 10 to 20: moderately productive water, with more algae and weed growth than an oligotrophic lake but rarely a bloom.
• Eutrophic, above 20: nutrient-rich water, prone to algal blooms and low oxygen at depth.

Loughborough Lake has 7 Lake Partner monitoring sites. Six have reported phosphorus for the three or more years the province requires before a status is assigned. Two of those sites are classified oligotrophic and four mesotrophic.

The longest record is held by site 6512/2 at E-1.8km East of Bridge, with phosphorus sampled several times a year between spring and fall over 20 years to 2022. Its long-term mean phosphorus concentration is 14.41 micrograms per litre, within the mesotrophic band, which runs from 10 to 20.

A Secchi disk is a white or black-and-white plate lowered on a marked line until it disappears from view. The depth at which it vanishes is the Secchi depth, a direct measure of water clarity. Clearer water gives a deeper reading.

The 103 clarity readings at site 6512/2 give a median Secchi depth of 4.0 meters.

Median Secchi depth by year at site 6512/2

See also Lake Water Quality and Blue-Green Algae in Ontario

Loughborough Lake Weather

The weather page for Loughborough Lake carries the forecast over the water, wave heights across the lake, and the modelled water temperature.

Loughborough Lake weather

Water temperature

Ontario’s aquatic resource records class Loughborough Lake as a warm-water lake, with a mean depth of 2.1 meters against its maximum of 4.6.

A lake separates into layers through the summer where it is deep enough. Sunlight and wind warm and mix the upper few meters, and beneath a band of rapid cooling, the thermocline, the water stays cold. A shallow lake mixes to the bottom instead and warms through, sooner in spring and later into autumn.

No provincial monitoring station records water temperature on Loughborough Lake. The LastLake model computes the temperature of its surface water for each day from the daily mean air temperature at Environment Canada’s Kingston Climate climate station, 30 kilometers from the lake, or the next nearest station when its record is incomplete, and from the lake’s area of 1,141 hectares and its mean depth of 2.1 meters.

Each day’s figure carries the model’s typical error for that month on lakes of the same size. The figure in the chart below is the temperature near the surface, away from the shoreline. Bays, shallows and water deeper below the surface differ in temperature. Temperature is not measured when ice covers the lake. The weather page for Loughborough Lake carries the model’s figures for the past weeks and the coming week.

See also Lake Water Temperature in Ontario

Fish in Loughborough Lake

Ontario’s aquatic resource records name 14 fish species in Loughborough Lake. The province’s other records for the lake name four further species, among them splake, brook trout and muskellunge. They appear in the records below.

Popular species in the province’s records

• Lake Trouttrout and whitefish
• Ciscotrout and whitefish
• Northern Pikepike
• Yellow Perchperch
• Smallmouth Basssunfish
• Largemouth Basssunfish
• Black Crappiesunfish
• Rock Basssunfish
• Pumpkinseedsunfish
• Bluegillsunfish
• Brown Bullheadcatfish

Spawning areas

Ontario maps 3 fish spawning records within the Loughborough Lake outline: 3 sunfish family spawning areas covering 0.24 hectares.

By number of records

By area mapped

• Sunfish family3 areas0.2 ha

The federal Fisheries Act prohibits the harmful alteration, disruption or destruction of fish habitat without an authorization, so a dock, dredging, infill or shoreline work at a mapped spawning area is reviewed on that basis.

Stocking history

Ontario’s stocking records for Loughborough Lake run from 1946 to 2015 and hold 91 releases. Lake Trout account for most of the fish: 811,336 released in 47 of the years between 1946 and 2015. The last recorded release was 7,500 lake trout yearlings in 2015.

Eating the fish

The 2026 Guide to Eating Ontario Fish carries consumption advice for five species taken from Loughborough Lake, tested for contaminants at a sampling location in Storrington Twp., Frontenac Co. Each figure below is the most meals a month the guide advises for a fish of that length. Where mercury sets the advice, the figure falls as the fish gets longer, because mercury accumulates over a fish’s life. Where the guide has no result yet for certain contaminants at a location, it sets a precautionary limit of 16 meals a month. A zero means the guide advises no meals of that fish at that size.

General population: adultsSensitive population: children under fifteen, women who are or may become pregnant

Fisheries Management Zone 18

Loughborough Lake lies in Fisheries Management Zone 18. Ontario sets its fishing seasons and catch limits by zone.

Fisheries management zones around Loughborough Lake

Where a row reads zone-wide, the zone’s own season or limit above applies.

See also Fishing Seasons in Ontario, Zone by Zone and Fish Stocking in Ontario Lakes

Loughborough Lake Ice Fishing

An ice hut on Loughborough Lake must be removed by March 15. The province sets dates for ice hut removal as a safety measure to ensure huts are removed before thawing occurs. One date applies to an entire fisheries management zone (FMZ). Loughborough Lake lies within FMZ 18.

An ice hut must also be removed before the ice breaks up, whether or not that date has passed. The deadline clears huts from the ice ahead of the thaw and does not close the fishing season.

Registration is required in FMZ 18 for an ice hut built of anything other than fabric, and for a fabric tent covering seven square meters or more. Registration is free, and the number is displayed on the outside of the hut.

Ice conditions

No public record reports the thickness or the condition of the ice on Loughborough Lake on any given day. Ontario publishes ice safety guidance for anyone going out on the ice, at ontario.ca.

See also Lake Ice in Ontario and When the Lakes Will Freeze This Winter

Islands and names

Loughborough Lake contains 105 islands in the Ontario Hydro Network’s outline, one of them over 10 hectares and 38 under a tenth of a hectare. Five of them lie mostly inside wetland the province’s Wetland With Significance dataset maps as marsh or open water.

Official names

Ontario’s geographic names register lists 49 official names on the water and its islands: 42 islands and seven bays. A further 3 named points stand on the mainland shore.

Bays 7

• Barrs Bay
• Battersea Bay
• Cunningham Bay
• Long Bay
• Millers Bay
• Round Lake Bay
• Sleeths Bay

Points on the shore 3

• Gilmour Point
• Johnsons Point
• Sampsons Point

Nearby lakes

• Dog Lake7 km away
• Sydenham Lake11 km away
• Devil Lake14 km away
• Whitefish Lake16 km away

All lakes

Questions about Loughborough Lake

• How deep is Loughborough Lake?

  Its deepest charted contour is 4.6 meters, and the water within it is deeper.

• How big is Loughborough Lake?

  Its surface covers 11.4 square kilometers and it holds 105 islands. Of its 87 kilometers of shoreline, 52 kilometers is the mainland shore and 35 kilometers is the shore of the islands.

• What fish are in Loughborough Lake?

  Ontario’s aquatic resource records name fourteen species, among them lake trout, smallmouth bass, largemouth bass, northern pike, yellow perch and black crappie. The lake’s spawning, consumption and stocking records also name splake, brook trout, muskellunge and rainbow trout.