Lake Seminary
Lake Seminary in Seminole County, Florida has a water quality grade of B (Good). Water clarity: 12.5 ft visibility. Phosphorus: 13 µg/L.
- Clarity
- 12.5 ft
- Typical in August
- 89°F
- Type
- Mesotrophic
- Trend
- ↓ Declining
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Lake Seminary is a mesotrophic lake in Seminole County, Florida. Water quality is graded B based on 1 sampling years through 2025. Overall water quality is declining over recent sampling years. Compared to the 121 other monitored lakes in Seminole County, Lake Seminary ranks #66 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2025-05-19. Grade methodology: LakeQuality 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)
Good clarity, visible to about 12.5 ft. Phosphorus level: 13 µg/L. Trophic State Index: 41.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 12.5 ft | Not graded |
| Phosphorus | 13 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 41 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Lake Seminary
Compare lakeside cabins, hotels, and vacation rentals near Lake Seminary in Seminole County, Florida — 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 Lake Seminary
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 Florida’s top lakes →
Water Temperature
Lake Seminary typically sits around 89°F at the surface in August. Summer average is about 87°F. Usually warmest in Aug (about 89°F) and coldest in Feb (about 66°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 52 field readings (2010–2025) via the EPA Water Quality Portal. See the full Lake Seminary water temperature breakdown →
Fishing Lake Seminary
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.15 m/yr | 6 |
| Phosphorus | ↓ Declining | +2.14 µg/L/yr | 6 |
EPA Impairment Status
Lake Seminary is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 4C).
Causes of impairment
Source: EPA ATTAINS assessment unit FL29976 · Official waterbody report
County Ranking
Ranked #66 of 122 lakes in Seminole County
Nearby Lakes in Seminole County
Frequently asked questions about Lake Seminary
Where is Lake Seminary?
- Lake Seminary is a lake in Seminole County, Florida. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Lake Seminary?
- Lake Seminary in Seminole County, Florida has a water quality grade of B (Good). Water clarity: 12.5 ft visibility. Phosphorus: 13 µg/L.
Is Lake Seminary safe to swim in?
- Good for swimming, clear water with low algae levels. Lake Seminary has a water quality grade of B (Good). Always check local health department advisories before swimming.
What is the water temperature of Lake Seminary?
- Lake Seminary typically sits around 89°F at the surface in August, from 52 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
Explore Lake Seminary across LakeQuality
Planning a trip around Canaveral?
Lake Seminary is about 38 miles from Canaveral National Seashore. Crowds there swing hard by season, so the month you pick changes both how busy the park is and what lodging costs.
Best time to visit Canaveral →More Florida Lake Rankings
Other Grade B Lakes in Florida
Mesotrophic Lakes in Florida
Where this data comes from
37 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Submitting organization not recorded for these samples37 samples · 2020–2025
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