O'Connors Lake
O'Connors Lake in Washington County, Minnesota has a water quality grade of B (Good). Water clarity: 6.6 ft visibility. Phosphorus: 32 µg/L. Chlorophyll-a (algae): 13.5 µg/L.
- Clarity
- 6.6 ft
- Typical in August
- 81°F
- Type
- Eutrophic
- Public access
- No
Next lake in Washington County
O'Connors Lake is a productive, nutrient-rich eutrophic lake in Washington County, Minnesota. Water quality is graded B based on 2 sampling years through 2024. Limited fish-species data available. No public access — the lake is private or restricted. Compared to the 74 other monitored lakes in Washington County, O'Connors Lake ranks #24 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-09-30. 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.
Good for swimming, clear water with low algae levels
Water Quality Grade: B (Good)
Murky, only visible to about 6.6 ft. Phosphorus level: 32 µg/L. Chlorophyll-a: 13.5 µg/L. Trophic State Index: 53.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 6.6 ft | Not graded |
| Phosphorus | 32 µg/L | Good |
| Chlorophyll-a (Algae) | 13.5 µg/L | Good |
| Trophic State Index (TSI) | 53 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near O'Connors Lake
Compare lakeside cabins, hotels, and vacation rentals near O'Connors Lake in Washington 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.
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Water Temperature
O'Connors Lake typically sits around 81°F at the surface in August. Summer average is about 78°F. Usually warmest in Jul (about 82°F) and coldest in May (about 62°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 17 field readings (2011–2024) via the EPA Water Quality Portal. See the full O'Connors Lake water temperature breakdown →
Fishing O'Connors Lake
County Ranking
Ranked #24 of 75 lakes in Washington County
Nearby Lakes in Washington County
Frequently asked questions about O'Connors Lake
What is the water quality grade for O'Connors Lake?
- O'Connors Lake in Washington County, Minnesota has a water quality grade of B (Good). Water clarity: 6.6 ft visibility. Phosphorus: 32 µg/L. Chlorophyll-a (algae): 13.5 µg/L.
Is O'Connors Lake safe to swim in?
- Good for swimming, clear water with low algae levels. O'Connors Lake has a water quality grade of B (Good). Algae concentration (chlorophyll-a) is 13.5 µg/L. Always check local health department advisories before swimming.
What is the water temperature of O'Connors Lake?
- O'Connors Lake typically sits around 81°F at the surface in August, from 17 EPA Water Quality Portal field readings (2011–2024). That is a typical value for the month, not a live reading.
Explore O'Connors Lake across LakeGrade
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Species activity outlook by water temperature and season
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High nutrients, frequent algae, reduced clarity
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Where this data comes from
23 measurements from 1 monitoring station, 2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA23 samples · 2024
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- Analysis of Chlorophyll in Periphyton and Plankton
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.