Lake Arnold
Lake Arnold in Orange County, Florida has a water quality grade of B (Good). Water clarity: 3.1 ft visibility. Phosphorus: 20.5 µg/L.
- Clarity
- 3.1 ft
- Typical in August
- 79°F
- Type
- Eutrophic
- Trend
- ↑ Improving
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Lake Arnold is a productive, nutrient-rich eutrophic lake in Orange County, Florida. Water quality is graded B based on 1 sampling years through 2025. Overall water quality is improving over recent sampling years. Compared to the 319 other monitored lakes in Orange County, Lake Arnold ranks #150 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2025-04-24. 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 Arnold never exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 0% of 24 samples across 7 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 3.1 ft of visibility. Phosphorus level: 20.5 µg/L. Trophic State Index: 54.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.1 ft | Not graded |
| Phosphorus | 20.5 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 54 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Lake Arnold
Compare lakeside cabins, hotels, and vacation rentals near Lake Arnold in Orange 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 Arnold
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Planning a whole trip? See where to stay at Florida’s top lakes →
Water Temperature
Lake Arnold typically sits around 79°F at the surface in August. Summer average is about 82°F. Usually warmest in Jul (about 88°F) and coldest in Jan (about 63°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 193 field readings (2010–2025) via the EPA Water Quality Portal. See the full Lake Arnold water temperature breakdown →
Fishing Lake Arnold
Water Quality Trend: ↑ Improving
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.348 m/yr | 5 |
| Phosphorus | ↑ Improving | -5.95 µg/L/yr | 5 |
EPA Impairment Status
Lake Arnold is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5A).
Causes of impairment
Source: EPA ATTAINS assessment unit FL3168Z3 · Official waterbody report
County Ranking
Ranked #150 of 320 lakes in Orange County
Nearby Lakes in Orange County
Frequently asked questions about Lake Arnold
Where is Lake Arnold?
- Lake Arnold is a lake in Orange 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 Arnold?
- Lake Arnold in Orange County, Florida has a water quality grade of B (Good). Water clarity: 3.1 ft visibility. Phosphorus: 20.5 µg/L.
Is Lake Arnold safe to swim in?
- Based on E. coli testing, Lake Arnold never exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 0% of 24 samples across 7 seasons. That works out to a bacteria swim-safety grade of A — a historical summary of past testing, not a current reading. Lake Arnold 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 Arnold?
- Lake Arnold typically sits around 79°F at the surface in August, from 193 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
Explore Lake Arnold across LakeQuality
Planning a trip around Canaveral?
Lake Arnold is about 40 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
Eutrophic Lakes in Florida
Where this data comes from
61 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 samples37 samples · 2020–2025
- Submitting organization not recorded for these samples24 samples · 2024–2025
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