Skaneateles Lake algae bloom history
New York's Department of Environmental Conservation listed Skaneateles Lake as having a harmful algal bloom every year from 2017 to 2025.
In 5 years, a bloom here was confirmed with high toxin levels, the most serious category the state recorded (tracked from 2012 to 2018).
Blooms were confirmed by state staff in 9 years; in the other years they were reported as suspicious but not confirmed.
Blooms have been recorded every year for the last 9 years in the data.
That puts Skaneateles Lake in the top 20% of the 352 New York lakes on this site for the number of years with blooms.
- 2017 High toxins, 12 reports
- 2018 High toxins, 8 reports
- 2019 Confirmed, 3 reports
- 2020 Confirmed, 23 reports
- 2021 Confirmed, 65 reports
- 2022 Confirmed, 9 reports
- 2023 Confirmed, 19 reports
- 2024 Confirmed, 149 reports
- 2025 Confirmed, 47 reports
When do algae blooms happen at Skaneateles Lake?
At Skaneateles Lake, reports are most often logged in July, August and September.
About 100% of reports fall between May and September, when warm, calm, sunny weather lets blue-green algae multiply.
Blooms can appear, move with the wind and fade within hours or days, so the time of year is only a guide.
Recent Skaneateles Lake algae reports
New York publishes one entry per lake for each season it appears on the bloom list, showing when it was first and last listed and its highest status.
| Date | Result |
|---|---|
| 22 August 2025 to 29 September 2025 | Confirmed bloom |
| 29 July 2024 to 18 October 2024 | Confirmed bloom |
| 23 August 2023 to 18 October 2023 | Confirmed bloom |
| 10 August 2022 to 3 October 2022 | Confirmed bloom |
| 11 August 2021 to 6 October 2021 | Confirmed bloom |
| 10 August 2020 to 9 October 2020 | Confirmed bloom |
| 2 September 2019 to 20 September 2019 | Confirmed bloom |
| 10 August 2018 to 20 October 2018 | Confirmed bloom, high toxins |
| 10 August 2018 to 14 September 2018 | Confirmed bloom, high toxins |
| 15 September 2017 to 27 October 2017 | Confirmed bloom, high toxins |
| 8 September 2017 to 13 October 2017 | Confirmed bloom, high toxins |
| 8 September 2017 to 13 October 2017 | Confirmed bloom, high toxins |
What the New York results mean
New York sorts each bloom by how far it has been checked.
- Suspicious bloom
- Reported to the state but not yet confirmed as blue-green algae.
- Confirmed bloom
- State staff confirmed blue-green algae from photos or a sample. Avoid contact where the bloom is.
- High toxins
- Toxin levels high enough to be a health concern. Recorded separately from 2012 to 2018.
Is Skaneateles Lake safe for dogs?
Dogs are at the greatest risk from toxic algae. They swallow water while swimming, eat scum on the shore and lick algae off their fur afterwards, and a small amount can kill a dog within hours. With blooms recorded in 9 different years here, take particular care at Skaneateles Lake in July, August and September.
- Keep your dog on a lead near water that looks green, scummy, foamy or discoloured, and away from algae washed up on the shore.
- If your dog gets in, rinse it straight away with clean water and don't let it lick its coat.
- Call a vet immediately if your dog vomits, drools, has diarrhoea, staggers, shakes or seems weak after being near the water.
Health effects of toxic algae
Blue-green algae (cyanobacteria) can produce toxins that affect the liver, nervous system and skin. Swallowing water during a bloom can cause stomach pain, vomiting and diarrhoea. Skin contact can cause rashes, and breathing spray from the water can irritate the eyes, nose and throat. Children are at higher risk because they are smaller and more likely to swallow water.
How to spot a bloom
Toxic blooms can look like pea soup, spilled paint or green streaks on the surface, and they can also be blue, brown, white or red. Scum often collects along the shore downwind. If you can't see your feet in knee-deep water, or you aren't sure, stay out.
Don't drink untreated lake water, and don't boil it to make it safe: boiling doesn't destroy algal toxins. If you feel unwell after contact with the water, contact a doctor or Poison Control on 1-800-222-1222.
Nearby lakes with algae reports
- Otisco Lake6 km away, 9 reports, last in 2025
- Owasco Lake15 km away, 12 reports, last in 2025
- Sucker Brook16 km away, 3 reports, last in 2025
- Song Lake18 km away, 13 reports, last in 2025
- Tully Lake19 km away, 13 reports, last in 2025
Questions about Skaneateles Lake
Is there algae in Skaneateles Lake right now?
Skaneateles Lake was on New York's harmful algal bloom list from 22 August 2025 to 29 September 2025, with confirmed bloom status (47 reports). New York publishes its data once a year, so for today's conditions check the NYHABS map and the signs at the shore.
When was the last algae bloom at Skaneateles Lake?
The most recent entry in New York's data is from 22 August 2025: a confirmed bloom.
Has Skaneateles Lake had toxic algae before?
Yes. Blooms are recorded every year from 2017 to 2025, most often in July, August and September.
Can dogs swim in Skaneateles Lake?
Keep dogs out of the water whenever a bloom is reported or the water looks green, scummy or discoloured. Dogs are the animals most often killed by algal toxins because they swallow water and lick their fur. If your dog swims in water that might have algae, rinse it with clean water and call a vet if it vomits, drools, staggers or seems weak.
Can you eat fish caught in Skaneateles Lake during a bloom?
If you keep fish caught during a bloom, health agencies advise removing the guts and liver and rinsing the fillets in clean water before cooking, because toxins collect most in the organs. Some agencies advise not eating fish from an active bloom at all, so follow local guidance.
About this data
This page uses official records from the New York State Department of Environmental Conservation (DEC), which published as a yearly summary; the current season is shown on the NYHABS map. Reports are grouped by waterbody, and Skaneateles Lake combines reports from Cayuga County, Cortland County and Onondaga County. The site was last rebuilt on 24 October 2026.
States only test some lakes, some of the time, so a lake without a recent report hasn't necessarily been checked. This page is independent, isn't affiliated with the State of New York, and isn't health advice. View the source data.