Lynch Lake
Lynch Lake in Washington County, Minnesota has a water quality grade of C (Fair). Water clarity: 5.8 ft visibility. Phosphorus: 33 µg/L. Chlorophyll-a (algae): 9.8 µg/L.
- Clarity
- 5.8 ft
- Typical in August
- 71°F
- Type
- Eutrophic
- Public access
- No
Next lake in Washington County
Lynch Lake is a productive, nutrient-rich eutrophic lake in Washington County, Minnesota. Water quality is graded C 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, Lynch Lake ranks #41 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-10-22. Grade methodology: LakeGrade methodology.
Watch Lynch Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
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)
Murky, only visible to about 5.8 ft. Phosphorus level: 33 µg/L. Chlorophyll-a: 9.8 µg/L. Trophic State Index: 53.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 5.8 ft | Not graded |
| Phosphorus | 33 µg/L | Fair |
| Chlorophyll-a (Algae) | 9.8 µg/L | Fair |
| Trophic State Index (TSI) | 53 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Lynch Lake
Compare lakeside cabins, hotels, and vacation rentals near Lynch 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.
Top-rated places to stay near Lynch 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
Lynch Lake typically sits around 71°F at the surface in August. Summer average is about 69°F. Usually warmest in Jul (about 71°F) and coldest in Apr (about 49°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 262 field readings (2010–2024) via the EPA Water Quality Portal. See the full Lynch Lake water temperature breakdown →
Fishing Lynch Lake
EPA Impairment Status
Lynch 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 MN82-0042-00 · Official waterbody report
County Ranking
Ranked #41 of 75 lakes in Washington County
Nearby Lakes in Washington County
Frequently asked questions about Lynch Lake
What is the water quality grade for Lynch Lake?
- Lynch Lake in Washington County, Minnesota has a water quality grade of C (Fair). Water clarity: 5.8 ft visibility. Phosphorus: 33 µg/L. Chlorophyll-a (algae): 9.8 µg/L.
Is Lynch Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Lynch Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 9.8 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Lynch Lake?
- Lynch Lake typically sits around 71°F at the surface in August, from 262 EPA Water Quality Portal field readings (2010–2024). That is a typical value for the month, not a live reading.
Explore Lynch Lake across LakeGrade
Fish species and top-graded lakes across Minnesota
Fish species and best lakes in Washington County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its grade
Lakes in the St. Croix Watershed, ranked by water quality
High nutrients, frequent algae, reduced clarity
Minnesota's cleanest and most-polluted lakes, ranked
More Minnesota Lake Rankings
State Parks Near Lynch Lake
Other Grade C Lakes in Minnesota
Eutrophic Lakes in Minnesota
Where this data comes from
84 measurements from 2 monitoring stations, 2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA84 samples · 2024
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- Analysis of Chlorophyll in Periphyton and Plankton
Monitoring station identifiers (2)
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