June Lake: toxic algae advisories
June Lake, Mono County. See all Mono County waters.
What the state's records say
The state's latest record, from Oct 7, 2026, recommends no advisory.
That reflects what the state knew on that date. It is not a finding that the water is safe now: blooms can return within days, and many are never reported.
Before you go, check the state's official algae page and any signs posted at the water.
Dogs at June Lake
The state's latest record, from Oct 7, 2026, recommends no advisory. For June Lake, that is not the same as an all-clear for today. Look at the water before your dog goes in: keep it out of green, blue-green or scummy water and away from mats on the shore.
Satellite estimate (not an advisory)
Week ending Sep 19, 2026: about 6,900 cells/mL of cyanobacteria near the center of June Lake.
A satellite estimate from EPA CyAN for a 1.2 km² lake. It does not measure toxins and does not change the advisory status.
| Week ending | Estimate |
|---|---|
| Sep 19, 2026 | about 6,900 cells/mL |
| Jan 17, 2026 | about 14,000 cells/mL |
| Feb 22, 2025 | about 39,000 cells/mL |
| Feb 15, 2025 | about 9,600 cells/mL |
| Feb 8, 2025 | about 180,000 cells/mL |
| Jan 25, 2025 | about 18,000 cells/mL |
| Jan 18, 2025 | about 32,000 cells/mL |
| Nov 30, 2024 | about 290,000 cells/mL |
This is a satellite estimate from the U.S. EPA's Cyanobacteria Assessment Network, not an advisory. It estimates how much cyanobacteria is in the water near the lake's center, not whether toxins are present: a high number does not mean toxins, and a low one does not mean there are none. It covers lakes of about 1 square kilometer and larger, so small ponds, dog parks and most rivers are not covered, and clouds can hide a lake for weeks. It never changes the advisory status above.
Satellite estimates: U.S. EPA Cyanobacteria Assessment Network (CyAN), from Copernicus Sentinel-3 data. Provisional, research-level estimates; EPA does not endorse this site. Checked Oct 22, 2026.
Reported spots
The state records each report at a spot, such as a beach or a boat ramp. Each spot's latest deciding record:
| Spot | Status |
|---|---|
| Beach | The state's latest record, from Oct 7, 2026, recommends no advisory. |
| June Lake beach | The state's latest record, from Aug 29, 2022, recommends no advisory. |
| beach | The state's latest record, from Jun 24, 2021, recommends no advisory. |
Advisory history
Every advisory record the state has published for June Lake, newest first. "None" is the state's record that no advisory was recommended on that date. "NA" records do not change a status.
| Date | Spot | State's level | Notes |
|---|---|---|---|
| Oct 7, 2026 | Beach | None | Advisory based on visual and toxins |
| Sep 2, 2026 | Beach | None | Advisory based on visual and toxins |
| Jun 18, 2026 | Beach | None | No cyano bloom w/testing; Updates from routine monitoring program-organization |
| Oct 23, 2025 | Beach | None | No cyano bloom w/testing; Updates from routine monitoring program-organization |
| Aug 29, 2025 | Beach | None | No cyano bloom w/testing; Updates from routine monitoring program-organization |
| Jun 25, 2025 | Beach | None | No cyano bloom w/testing; Updates from routine monitoring program-organization |
| Oct 4, 2024 | Beach | None | No cyano bloom w/testing; Updates from routine monitoring program-organization |
| Aug 22, 2024 | Beach | None | No cyano bloom w/testing; Updates from routine monitoring program-organization |
| Jun 27, 2024 | Beach | None | No cyano bloom w/testing; Updates from routine monitoring program-organization |
| Aug 22, 2023 | Beach | None | No cyano bloom w/testing; Updates from routine monitoring program-organization |
| Jun 27, 2023 | Beach | None | No cyano bloom w/testing; Updates from routine monitoring program-organization |
| Aug 29, 2022 | June Lake beach | None | Updates from routine monitoring program-organization |
| Aug 29, 2022 | June Lake beach | None | No cyano bloom w/testing |
| Aug 17, 2022 | June Lake beach | None | visual monitoring based advisory |
| Jun 29, 2022 | June Lake beach | None | No cyano bloom w/testing |
| May 26, 2022 | June Lake beach | None | Updates from routine monitoring program-organization |
| Jun 24, 2021 | beach | None | Testing results below posting triggers |
Source
Advisory data: California State Water Resources Control Board, Freshwater Harmful Algal Bloom Program, via data.ca.gov (public domain). Advisories are recommendations; reporting is voluntary and incomplete. The state's data. An advisory ends only when the state records a later "None" (no advisory recommended) at the same spot, or an end date. A blank end date is unknown.