Juno Lake
Cass County, Michigan241 acresView mapDirections
Nutrients and algae sit mid-range for this region.
- Eutrophic
- Impaired · Mercury
- #7 of 10 in the county
Juno Lake in Cass County, Michigan has a water quality grade of C (Fair). Water clarity: 7.5 ft visibility. Phosphorus: 22 µg/L. Chlorophyll-a (algae): 8.2 µg/L. Surface area: 240.8 acres.
- Clarity
- 7.5 ft
- Typical in September
- 67°F
- Area
- 241 acres
- Type
- Eutrophic
- Phosphorus
- 22 µg/L
- Chlorophyll-a
- 8.2 µg/L
- Trend
- → Stable
Stays via Stay22
Stays near Juno Lake
Compare lakeside cabins, hotels, and vacation rentals near Juno Lake in Cass County, Michigan — 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 Juno Lake
Prices for Sep 11–13, 4 adults. Change dates on the map below.
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 Michigan’s top lakes →
Watch Juno Lake’s letter
Email me if this lake’s grade moves. Grades stay free.
Or email
Juno Lake is a 241-acre productive, nutrient-rich eutrophic lake in Cass County, Michigan. Water quality is graded C based on 2 sampling years through 2023. Water clarity is improving over recent sampling years. Compared to the 9 other monitored lakes in Cass County, Juno Lake ranks #7 for water quality.
Source: EPA Water Quality Portal sampling records, EGLE, last sampled 2023-09-20. Grade methodology: LakeQuality methodology.
Swimming Safety
Grade onlyModerate
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.
The C is nutrients and algae, not a swimming clearance. Juno Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Water Quality Grade: C (Fair)
Moderate clarity, visible to about 7.5 ft. Phosphorus 22 µg/L. Chlorophyll-a 8.2 µg/L. TSI 49. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 7.5 ft | Not graded |
| Phosphorus | 22 µg/L | Good |
| Chlorophyll-a (Algae) | 8.2 µg/L | Fair |
| Trophic State Index (TSI) | 49 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Water Temperature
Juno Lake typically sits around 67°F at the surface in September. Summer average is about 66°F. Usually warmest in Aug (about 69°F) and coldest in May (about 58°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 485 field readings (2012–2022) via the EPA Water Quality Portal. See the full Juno Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 241 acres |
No bathymetric survey has been published for Juno Lake, so its depth is not documented here.
Fishing Juno Lake
Water Quality Trend: → Stable
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.275 m/yr | 6 |
| Phosphorus | → Stable | +0.29 µg/L/yr | 5 |
| Chlorophyll-a | ↓ Declining | +0.9 µg/L/yr | 4 |
EPA Impairment Status
Juno Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MI040500011403-03 · Official waterbody report · Matched by proximity (0.27 km)
County Ranking
Ranked #7 of 10 lakes in Cass County
Nearby Lakes With Higher Grades
Juno Lake holds Grade C. 2 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Cass County
Frequently asked questions about Juno Lake
Where is Juno Lake?
- Juno Lake is a lake in Cass County, Michigan. LakeQuality grades it C for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Juno Lake?
- Juno Lake in Cass County, Michigan has a water quality grade of C (Fair). Water clarity: 7.5 ft visibility. Phosphorus: 22 µg/L. Chlorophyll-a (algae): 8.2 µg/L. Surface area: 240.8 acres.
Is Juno Lake safe to swim in?
- The C is nutrients and algae, not a swimming clearance. Juno Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
What is the water temperature of Juno Lake?
- Juno Lake typically sits around 67°F at the surface in September, from 485 EPA Water Quality Portal field readings (2012–2022). That is a typical value for the month, not a live reading.
Explore Juno Lake across LakeQuality
Fish species and top-graded lakes across Michigan
Fish species and best lakes in Cass County
Species activity outlook by water temperature and season
Where to stay at Michigan's top lakes, each with its grade
High nutrients, frequent algae, reduced clarity
Michigan's cleanest and most-polluted lakes, ranked
More Michigan Lake Rankings
Other Grade C Lakes in Michigan
Eutrophic Lakes in Michigan
Where this data comes from
99 measurements from 1 monitoring station, 2016–2023. Retrieved from the EPA Water Quality Portal on 2026-08-26.
Collected and reported by
- Michigan EGLE - MiCorps
21MICH_MICORPS99 samples · 2016–2023
Analytical methods
- Phosphorus by Colorimetry
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
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