Spirit Lake
Spirit Lake in St. Louis County, Minnesota has a water quality grade of C (Fair). Water clarity: 1.3 ft visibility. Phosphorus: 65 µg/L. Chlorophyll-a (algae): 1.8 µg/L.
- Clarity
- 1.3 ft
- Typical in August
- 71°F
- Type
- Eutrophic
- Public access
- Yes
Next lake in St. Louis County
Spirit Lake is a productive, nutrient-rich eutrophic lake in St. Louis County, Minnesota. Water quality is graded C based on 2 sampling years through 2025. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 67 other monitored lakes in St. Louis County, Spirit Lake ranks #51 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-22. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLimited data
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.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Very murky, less than 1.3 ft of visibility. Phosphorus level: 65 µg/L. Chlorophyll-a: 1.8 µg/L. Trophic State Index: 58.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.3 ft | Not graded |
| Phosphorus | 65 µg/L | Poor |
| Chlorophyll-a (Algae) | 1.8 µg/L | Good |
| Trophic State Index (TSI) | 58 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Spirit Lake
Compare lakeside cabins, hotels, and vacation rentals near Spirit Lake in St. Louis 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.
Top-rated places to stay near Spirit Lake
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Water Temperature
Spirit Lake typically sits around 71°F at the surface in August. Summer average is about 72°F. Usually warmest in Jul (about 78°F) and coldest in May (about 64°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 9 field readings (2025–2025) via the EPA Water Quality Portal. See the full Spirit Lake water temperature breakdown →
Recreation & Access
- Spirit/ Clyde AvenuePublic
Fishing Spirit Lake
EPA Impairment Status
Spirit Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MN69-1291-03 · Official waterbody report
County Ranking
Ranked #51 of 68 lakes in St. Louis County
Nearby Lakes in St. Louis County
Frequently asked questions about Spirit Lake
What is the water quality grade for Spirit Lake?
- Spirit Lake in St. Louis County, Minnesota has a water quality grade of C (Fair). Water clarity: 1.3 ft visibility. Phosphorus: 65 µg/L. Chlorophyll-a (algae): 1.8 µg/L.
Is Spirit Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Spirit Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 1.8 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Spirit Lake?
- Spirit Lake typically sits around 71°F at the surface in August, from 9 EPA Water Quality Portal field readings (2025–2025). That is a typical value for the month, not a live reading.
Are there boat ramps on Spirit Lake?
- Spirit Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Spirit/ Clyde Avenue. Public access is listed as yes.
Explore Spirit Lake across LakeGrade
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High nutrients, frequent algae, reduced clarity
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Where this data comes from
28 measurements from 1 monitoring station, 2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA28 samples · 2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 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)
Named boat-access points from the USGS National Boat Ramps inventory