Myrtle Lake
Seminole County, FloridaView mapDirections
Florida DEP publishes the water-quality measurements for Myrtle Lake. Here is what has been measured.
- Eutrophic
Myrtle Lake in Seminole County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 2.8 ft visibility. Phosphorus: 45 µg/L.
Myrtle Lake is a productive, nutrient-rich eutrophic lake in Seminole County, Florida. Water clarity is improving over recent sampling years. Compared to the 121 other monitored lakes in Seminole County, Myrtle Lake ranks #97 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2025-07-01. Methodology: how these readings are compared.
Swimming conditions
Readings onlyModerate algae
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Myrtle Lake is safe to swim in today is a call for the Florida Department of Environmental Protection and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Myrtle Lake
These are the measurements Florida DEP publishes for Myrtle Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 2.8 ft of visibility. Phosphorus 45 µg/L. TSI 61.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 2.8ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 45µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 61 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Myrtle Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Myrtle Lake typically sits around 79°F at the surface in October. Summer average is about 87°F. Usually warmest in Jul (about 87°F) and coldest in Jan (about 63°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (63°F) to its warmest (87°F).
Typical surface water temperature by month, from 84 field readings (2010–2025) via the EPA Water Quality Portal. See the full Myrtle Lake water temperature breakdown →
Stays via Stay22
Stays near Myrtle Lake
Compare lakeside cabins, hotels, and vacation rentals near Myrtle Lake 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 Myrtle Lake
Prices for Oct 16–18, 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 Florida’s top lakes →
Follow Myrtle Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing Myrtle Lake
Water Quality Trend: Stable
Based on 6 years of monitoring (2020–2025).
Water clarity
Improving6 years
Phosphorus
Worsening+4 µg/L/yr5 years
Nearby Lakes in Seminole County
Frequently asked questions about Myrtle Lake
Where is Myrtle Lake?
- Myrtle Lake is a lake in Seminole County, Florida. Its water-quality measurements are published by Florida DEP and shown on this page as reported.
What is the water quality of Myrtle Lake?
- Myrtle Lake in Seminole County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 2.8 ft visibility. Phosphorus: 45 µg/L.
Is Myrtle Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Myrtle Lake?
- Myrtle Lake typically sits around 79°F at the surface in October, from 84 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
Explore Myrtle Lake across LakeQuality
More lakes in Florida
Other Lakes in Florida
Eutrophic Lakes in Florida
Where this data comes from
82 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 samples82 samples · 2020–2025
Monitoring station identifiers (2)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.