Lake Tom John
Lake Tom John in Leon County, Florida has a water quality grade of B (Good). Water clarity: 1.6 ft visibility. Phosphorus: 25 µg/L.
- Clarity
- 1.6 ft
- Typical in August
- 88°F
- Type
- Eutrophic
- Trend
- → Stable
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Lake Tom John is a productive, nutrient-rich eutrophic lake in Leon County, Florida. Water quality is graded B based on 1 sampling years through 2025. Water clarity is declining over recent sampling years. Compared to the 58 other monitored lakes in Leon County, Lake Tom John ranks #28 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2025-06-25. Grade methodology: LakeQuality methodology.
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Swimming Safety
Grade onlyBacteria A
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.
Based on E. coli testing, Lake Tom John never exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 0% of 26 samples across 8 seasons.
This is a historical summary of past testing, not a current condition — bacteria levels change quickly, especially after rain. Always check Florida’s current beach and health-department advisories before swimming.
Water Quality Grade: B (Good)
Very murky, less than 1.6 ft of visibility. Phosphorus level: 25 µg/L. Trophic State Index: 60.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.6 ft | Not graded |
| Phosphorus | 25 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 60 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Lake Tom John
Compare lakeside cabins, hotels, and vacation rentals near Lake Tom John in Leon 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 Tom John
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Water Temperature
Lake Tom John typically sits around 88°F at the surface in August. Summer average is about 88°F. Usually warmest in Aug (about 88°F) and coldest in Feb (about 57°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 52 field readings (2016–2025) via the EPA Water Quality Portal. See the full Lake Tom John water temperature breakdown →
Fishing Lake Tom John
Water Quality Trend: → Stable
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.158 m/yr | 3 |
| Phosphorus | ↑ Improving | -4.08 µg/L/yr | 6 |
EPA Impairment Status
Lake Tom John is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit FL647A · Official waterbody report
County Ranking
Ranked #28 of 59 lakes in Leon County
Nearby Lakes in Leon County
Frequently asked questions about Lake Tom John
Where is Lake Tom John?
- Lake Tom John is a lake in Leon 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 Tom John?
- Lake Tom John in Leon County, Florida has a water quality grade of B (Good). Water clarity: 1.6 ft visibility. Phosphorus: 25 µg/L.
Is Lake Tom John safe to swim in?
- Based on E. coli testing, Lake Tom John never exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 0% of 26 samples across 8 seasons. That works out to a bacteria swim-safety grade of A — a historical summary of past testing, not a current reading. Lake Tom John has a water quality grade of B (Good). Bacteria levels can spike quickly after heavy rain, so always check Florida's current beach and health-department advisories before you swim.
What is the water temperature of Lake Tom John?
- Lake Tom John typically sits around 88°F at the surface in August, from 52 EPA Water Quality Portal field readings (2016–2025). That is a typical value for the month, not a live reading.
Explore Lake Tom John across LakeQuality
More Florida Lake Rankings
Other Grade B Lakes in Florida
Eutrophic Lakes in Florida
Where this data comes from
25 measurements from 2 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Submitting organization not recorded for these samples21 samples · 2020–2025
- Submitting organization not recorded for these samples4 samples · 2025
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