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LakeQuality

Hall Lake

F
Grade F — Algae-prone
Algae-prone · #4 of 12 lakes in the county · 3 ft clear · Eutrophic · 548 acres
Eutrophic

Hall Lake in Martin County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 3 ft visibility. Phosphorus: 96 µg/L. Chlorophyll-a (algae): 57.4 µg/L. Maximum depth: 27 ft. Surface area: 548.05 acres.

Clarity
3 ft
Typical in August
74°F
Max depth
27 ft
Area
548 acres
Type
Eutrophic
Trend
Stable
Public access
Yes
Ice-out
Mar 21
Open water
256 days

Grade F measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Hall Lake

Next lake in Martin County

FBudd Lake3.2 ft clear · Martin CountyView →
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Hall Lake is a 548-acre productive, nutrient-rich eutrophic lake in Martin County, Minnesota with a maximum depth of 27 feet. Water quality is graded F based on 2 sampling years through 2025. Water clarity is improving over recent sampling years. The lake supports 19 documented fish species including bigmouth buffalo, black bullhead, and black crappie. Public access is available. Compared to the 11 other monitored lakes in Martin County, Hall Lake ranks #4 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-30. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Algae risk

Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.

Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom

Compare the safest swimming lakes near Mankato

Get alerts for Hall Lake

Water Quality Grade: F (Algae-prone)

Very murky, less than 3 ft of visibility. Phosphorus level: 96 µg/L. Chlorophyll-a: 57.4 µg/L. Trophic State Index: 67.

MetricValueGrade
Water Clarity (Secchi Depth)3 ftNot graded
Phosphorus96 µg/LPoor
Chlorophyll-a (Algae)57.4 µg/LPoor
Trophic State Index (TSI)67Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Hall Lake

Compare lakeside cabins, hotels, and vacation rentals near Hall Lake in Martin County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Hall Lake are listed below.

Top-rated places to stay near Hall Lake

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Planning a whole trip? See where to stay at Minnesota’s top lakes →

Water Temperature

Hall Lake typically sits around 74°F at the surface in August. Summer average is about 76°F. Usually warmest in Jul (about 79°F) and coldest in Apr (about 50°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
50°
May
57°
Jun
74°
Jul
79°
Aug
74°
Sep
68°
Oct
51°
Nov
Dec

Typical surface water temperature by month, from 130 field readings (20172025) via the EPA Water Quality Portal. See the full Hall Lake water temperature breakdown →

Blue-Green Algae (Cyanobacteria)

No current satellite reading

There’s no recent EPA CyAN cyanobacteria estimate for Hall Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was very high (1,819,701 cells/mL) on July 19, 2026.

Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗

Lake Details

CharacteristicValue
Maximum Depth27 ft
Surface Area548 acres
Shoreline Length4.1 mi
Littoral Zone51%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
54 sq mi
Elevation
1,145 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).

Fish Species

Click a species to see every graded lake where it is documented.

Fishing Hall Lake

DNR Fisheries Survey Summary

12 surveys on file from MN DNR Fisheries. Most recent: 2023-09-22 (Targeted Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
SFS89.23
YLB44.250.17 lb
Black Bullhead18.040.52 lb
Freshwater Drum17.690.57 lb
Common Carp16.144.82 lb
Yellow Perch11.960.24 lb

CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.

Length Distributions

Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.

YLB

445 fish · 511 in · 2022-08-29
2281140567891011

Black Bullhead

2 fish · 88 in · 2022-08-29
2108

Freshwater Drum

51 fish · 518 in · 2022-08-29
2010056789101112131415161718

Common Carp

15 fish · 2131 in · 2022-08-29
6302122232425262728293031

From the 2023-09-22 survey

Walleye have been managed for many years in the Fairmont chain-of-lakes. Past stockings have included Walleye fry, fingerling, yearlings, and adults. Essentially, whatever life stage of Walleye was available they would be stocked into the lakes. However, since 2019 the Fairmont chain-of-lakes has been stocked with…

Source: MN DNR LakeFinder Fisheries Lake Survey

DNR Reports & Resources

Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Hall Lake. 3 reports on file.

These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).

Based on 6 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Improving+0.061 m/yr6
Phosphorus Stable-0.57 µg/L/yr6
Chlorophyll-a Declining+5.85 µg/L/yr6
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (29 observations).

Typical Ice-Out
Mar 21
Typical Ice-In
Dec 2

Estimated open water season: 256 days

EarliestLatest
Ice-Out2024-02-26 (2024)2018-04-29 (2018)
Ice-In2018-11-13 (2018)2015-12-19 (2015)

Most recent ice-out: 2026-03-10

EPA Impairment Status

Hall Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).

Causes of impairment

Impaired biota (cause unknown)Nutrients (phosphorus, nitrogen)

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit MN46-0031-00 · Official waterbody report

County Ranking

Ranked #4 of 12 lakes in Martin County

Nearby Lakes in Martin County

Frequently asked questions about Hall Lake

What is the water quality grade for Hall Lake?

Hall Lake in Martin County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 3 ft visibility. Phosphorus: 96 µg/L. Chlorophyll-a (algae): 57.4 µg/L. Maximum depth: 27 ft. Surface area: 548.05 acres.

Is Hall Lake safe to swim in?

Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom. Hall Lake has a water quality grade of F (Algae-prone). Algae concentration (chlorophyll-a) is 57.4 µg/L. Always check local health department advisories before swimming.

What is the water temperature of Hall Lake?

Hall Lake typically sits around 74°F at the surface in August, from 130 EPA Water Quality Portal field readings (2017–2025). That is a typical value for the month, not a live reading.

How deep is Hall Lake?

Hall Lake has a maximum depth of 27 feet. The lake covers 548.05 acres.

What fish are in Hall Lake?

Fish species found in Hall Lake include bigmouth buffalo, black bullhead, black crappie, bluegill, channel catfish, common carp, freshwater drum, green sunfish, largemouth bass, muskellunge, northern pike, orangespotted sunfish, quillback, walleye, white crappie, white sucker, yellow bass, yellow bullhead, yellow perch. Hall Lake is located in Martin County, Minnesota.

When does Hall Lake thaw?

Hall Lake typically has ice-out around Mar 21. Ice typically forms around Dec 2. The open water season is approximately 256 days.

Does Hall Lake have blue-green algae?

There is no recent EPA CyAN cyanobacteria estimate for Hall Lake (clouds, ice, or an off-season gap). The most recent reading was very high (1,819,701 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.

Eutrophic Lakes in Minnesota

Where this data comes from

98 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA98 samples · 2020–2025

Analytical methods

  • Field measurement/observation, generic method
  • Phosphorus by Colorimetry
  • 10200 H 3 ~ Chlorophyll a-b-c Determination by fluorometer
  • 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)

Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.

Other records on this page

Impairment status from EPA ATTAINS 303(d) database

Lake size & watershed from HydroLAKES (HydroSHEDS)

Lake details from Minnesota DNR LakeFinder

Ice data from Minnesota DNR Climate