Lake Temescal: toxic algae advisories
Lake Temescal, Alameda County. See all Alameda County waters.
What the state's records say
Danger advisory, last posted Oct 16, 2026. No all-clear recorded.
5 reported spots here have an advisory with no all-clear recorded.
Reporting is voluntary, so the state may not have recorded an end even if conditions changed. Check posted signs and the official map.
What this level asks: Toxins may be at levels that can seriously harm people and animals. Stay out of the water and keep children and pets away from the water and the shore.
Before you go, check the state's official algae page and any signs posted at the water.
Dogs at Lake Temescal
The state has an advisory on file for Lake Temescal (Danger advisory), last posted Oct 16, 2026, and no all-clear recorded. Keep your dog out of the water and away from scum on the shore until the state records an end.
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 |
|---|---|
| Lake Temescal | Danger advisory, last posted Oct 16, 2026. No all-clear recorded. |
| East Bay Regional Parks | The state recorded an end date of Dec 31, 2022. |
| Spot not described | The state's latest record, from Apr 15, 2022, recommends no advisory. |
| Spot not described | The state's latest record, from Jul 16, 2021, recommends no advisory. |
| Lake Temescal | Caution advisory, last posted Dec 31, 2020. No all-clear recorded. |
| Lake Temescal | Caution advisory, last posted Oct 24, 2019. No all-clear recorded. |
| Lake Temescal | The state's latest record, from Nov 27, 2018, recommends no advisory. |
| Lake Temescal | Caution advisory, last posted Dec 22, 2017. No all-clear recorded. |
| Lake Temescal | Danger advisory, last posted Dec 8, 2016. No all-clear recorded. |
Advisory history
Every advisory record the state has published for Lake Temescal, 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 16, 2026 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 9, 2026 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 1, 2026 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 25, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 18, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 11, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 3, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 31, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 21, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 14, 2026 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 7, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 31, 2026 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 24, 2026 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 17, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 10, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 3, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 26, 2026 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 26, 2026 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 19, 2026 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 12, 2026 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 12, 2026 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 5, 2026 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 1, 2026 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 22, 2026 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 15, 2026 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 8, 2026 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 1, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Apr 24, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Apr 16, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Apr 10, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Mar 20, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Mar 13, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Mar 6, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Feb 26, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Feb 20, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Feb 6, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 30, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 23, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 16, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 16, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 9, 2026 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Dec 19, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Dec 5, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Dec 5, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Dec 5, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Nov 20, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Nov 7, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Nov 7, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 31, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 23, 2025 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 17, 2025 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 10, 2025 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 10, 2025 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 26, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 19, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 12, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 5, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 29, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 22, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 18, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 8, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 31, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 24, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 18, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 11, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 26, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 20, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 13, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 6, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 2, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 19, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 9, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 2, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Apr 28, 2025 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Apr 23, 2025 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Apr 23, 2025 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Apr 11, 2025 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Apr 4, 2025 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Mar 28, 2025 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Mar 14, 2025 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Feb 28, 2025 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Feb 21, 2025 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Feb 14, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Feb 6, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 31, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 24, 2025 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 17, 2025 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 13, 2025 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 2, 2025 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Dec 20, 2024 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Dec 6, 2024 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Dec 2, 2024 | Lake Temescal | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Nov 12, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 31, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 18, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 11, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 4, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 27, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 20, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 13, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 6, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 30, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 15, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 6, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 2, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 26, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 22, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 11, 2024 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 3, 2024 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 24, 2024 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 24, 2024 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 24, 2024 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 21, 2024 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 3, 2024 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 28, 2024 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 24, 2024 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 13, 2024 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 13, 2024 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 6, 2024 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Apr 29, 2024 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Apr 23, 2024 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Apr 19, 2024 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Apr 10, 2024 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Apr 4, 2024 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Mar 25, 2024 | Lake Temescal | Warning | Lake-wide advisory; Updates from routine monitoring program-organization |
| Mar 20, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Mar 11, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Mar 8, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Mar 1, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Feb 20, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Feb 13, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Feb 9, 2024 | Lake Temescal | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 30, 2024 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 8, 2024 | Lake Temescal | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 8, 2024 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Jan 2, 2024 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Dec 20, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Dec 7, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Nov 27, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Nov 15, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Nov 3, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Oct 30, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Oct 23, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Oct 18, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Oct 3, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Sep 25, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Sep 18, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Sep 11, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Sep 5, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Aug 28, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Aug 21, 2023 | Lake Temescal | Caution | Updates from routine monitoring program-organization |
| Aug 14, 2023 | Lake Temescal | Caution | Updates from routine monitoring program-organization |
| Aug 7, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Aug 4, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Jul 24, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Jul 17, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Jul 10, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Jul 3, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Jun 29, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Jun 20, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Jun 5, 2023 | Lake Temescal | Danger | Updates from routine monitoring program-organization |
| Jun 5, 2023 | Lake Temescal | Warning | Updates from routine monitoring program-organization |
| May 30, 2023 | Lake Temescal | Caution | Updates from routine monitoring program-organization |
| May 22, 2023 | Lake Temescal | Caution | Updates from routine monitoring program-organization |
| May 15, 2023 | Lake Temescal | None | Updates from routine monitoring program-organization |
| May 8, 2023 | Lake Temescal | None | Updates from routine monitoring program-organization |
| May 3, 2023 | Lake Temescal | None | Updates from routine monitoring program-organization |
| Apr 24, 2023 | Lake Temescal | None | Updates from routine monitoring program-organization |
| Apr 17, 2023 | Lake Temescal | None | Updates from routine monitoring program-organization |
| Apr 10, 2023 | Lake Temescal | None | Updates from routine monitoring program-organization |
| Apr 3, 2023 | Lake Temescal | Caution | Updates from routine monitoring program-organization |
| Mar 27, 2023 | Lake Temescal | None | Updates from routine monitoring program-organization |
| Feb 27, 2023 | Lake Temescal | None | Updates from routine monitoring program-organization |
| Feb 1, 2023 | Lake Temescal | None | Updates from routine monitoring program-organization |
| Jan 27, 2023 | Lake Temescal | Caution | Updates from routine monitoring program-organization |
| Dec 30, 2022 | Lake Temescal | Caution | Updates from routine monitoring program-organization |
| Dec 27, 2022 | East Bay Regional Parks | Caution | End date recorded: Dec 31, 2022. Updates from routine monitoring program-organization |
| Dec 27, 2022 | East Bay Regional Parks | Caution | Updates from routine monitoring program-organization |
| Nov 29, 2022 | East Bay Regional Parks | Caution | Updates from routine monitoring program-organization |
| Nov 15, 2022 | East Bay Regional Parks | Caution | Updates from routine monitoring program-organization |
| Oct 31, 2022 | East Bay Regional Parks | Caution | Updates from routine monitoring program-organization |
| Oct 24, 2022 | East Bay Regional Parks | Caution | Updates from routine monitoring program-organization |
| Oct 17, 2022 | East Bay Regional Parks | Caution | Updates from routine monitoring program-organization |
| Oct 11, 2022 | East Bay Regional Parks | Caution | Updates from routine monitoring program-organization |
| Oct 7, 2022 | East Bay Regional Parks | Caution | Updates from routine monitoring program-organization |
| Oct 4, 2022 | East Bay Regional Parks | Caution | Updates from routine monitoring program-organization |
| Sep 19, 2022 | East Bay Regional Parks | Caution | Updates from routine monitoring program-organization |
| Sep 12, 2022 | East Bay Regional Parks | Caution | Updates from routine monitoring program-organization |
| Sep 6, 2022 | East Bay Regional Parks | Caution | Updates from routine monitoring program-organization |
| Aug 29, 2022 | East Bay Regional Parks | Caution | Updates from routine monitoring program-organization |
| Aug 22, 2022 | East Bay Regional Parks | Caution | Updates from routine monitoring program-organization |
| Aug 15, 2022 | East Bay Regional Parks | Caution | Updates from routine monitoring program-organization |
| Aug 8, 2022 | East Bay Regional Parks | Caution | Updates from routine monitoring program-organization |
| Aug 1, 2022 | East Bay Regional Parks | Caution | Updates from routine monitoring program-organization |
| Jul 25, 2022 | East Bay Regional Parks | Caution | Updates from routine monitoring program-organization |
| Jul 22, 2022 | East Bay Regional Parks | Caution | Updates from routine monitoring program-organization |
| Jul 18, 2022 | East Bay Regional Parks | Caution | visual monitoring based advisory |
| Jul 15, 2022 | East Bay Regional Parks | Caution | visual monitoring based advisory |
| Jul 5, 2022 | East Bay Regional Parks | Caution | visual monitoring based advisory |
| Jul 1, 2022 | East Bay Regional Parks | Caution | visual monitoring based advisory |
| Jun 22, 2022 | East Bay Regional Parks | Caution | visual monitoring based advisory |
| Jun 13, 2022 | East Bay Regional Parks | Caution | |
| Jun 6, 2022 | East Bay Regional Parks | Caution | |
| Jun 1, 2022 | East Bay Regional Parks | Caution | |
| May 23, 2022 | East Bay Regional Parks | Caution | |
| May 17, 2022 | East Bay Regional Parks | Caution | |
| May 9, 2022 | East Bay Regional Parks | None | |
| May 2, 2022 | East Bay Regional Parks | None | |
| Apr 15, 2022 | Spot not described | None | Testing results below posting triggers |
| Jul 16, 2021 | Spot not described | None | Testing results below posting triggers |
| Dec 31, 2020 | Lake Temescal | Caution | Advisory based on visual and toxins |
| Oct 24, 2019 | Lake Temescal | Caution | |
| Nov 27, 2018 | Lake Temescal | None | |
| Dec 22, 2017 | Lake Temescal | Caution | |
| Dec 8, 2016 | Lake Temescal | Danger |
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.