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Sign In Create free accountThe most current, independently verified data on Sayulita water quality and Sayulita ocean quality. If you've been wondering whether Sayulita's beaches are clean, polluted, or safe to swim — this page gives you the lab-certified facts, updated every month.
The data on this page comes from independent water-quality testing performed by a certified Mexican laboratory. Samples are taken monthly from Playa Principal (Sayulita's main beach) and the North Side (the river-mouth end of the bay), then analyzed for fecal coliform bacteria — the standard indicator used worldwide to determine whether ocean water is safe for swimming and recreation.
This testing program is paid for entirely by Pro Sayulita, the local non-profit that funds the cleanup, infrastructure, and stewardship work that keeps Sayulita beautiful. Pro Sayulita is funded purely by donations from homeowners, residents, and local businesses. If you love Sayulita and aren't yet a member, please join or donate today — the testing you see below would not exist without that community support.
NMP stands for "Número Más Probable" — the Spanish term for "Most Probable Number" (MPN in English). It's the standard statistical method used by water-quality laboratories worldwide to estimate how many fecal coliform bacteria are present in a 100-milliliter sample of water.
Lower numbers mean cleaner water. Mexican federal recreational-water guidelines (NOM-001-SEMARNAT) consider readings under 200 NMP/100ml safe for swimming and direct contact. Anything above that is flagged as potentially polluted and worth a second look.
Below is the complete record of the most recent independent test results for both sampling sites. The newest reading is highlighted at the top.
Excellent (under 50) Acceptable (50–200) Elevated (over 200)
| Test Date | Playa Principal (NMP/100ml) |
North Side (NMP/100ml) |
|---|---|---|
| April 16, 2026 — Latest | 37 | 32 |
| March 13, 2026 | 8 | 60 |
| February 18, 2026 | 23 | 9 |
| January 16, 2026 | 39 | 69 |
| December 15, 2025 | 33 | 26 |
| November 18, 2025 | 5 | 642 |
| October 14, 2025 | 49 | 382 |
| September 12, 2025 | 18 | 4 |
| August 13, 2025 | 4 | 14 |
| July 14, 2025 | 196 | 3 |
| June 15, 2025 | 9 | 7 |
| May 17, 2025 | 29 | 150 |
| April 5, 2025 | 5 | 60 |
Reading the data: Playa Principal (Sayulita's main beach) has tested well within Mexican safe-swimming limits in every monthly test. The North Side sampling point — located near the river mouth — shows occasional elevated readings during the late-rainy-season months (October and November), when runoff from the watershed is at its highest. By December, levels return to safe ranges. The most recent April 2026 results show both beaches well within safe limits.
It's a fair question, and one of the most-searched topics about the town. Online forums and travel sites occasionally raise concerns about Sayulita dirty water, a polluted Sayulita beach, or whether the Sayulita ocean is safe to swim in. The honest, data-driven answer based on monthly lab testing is this:
Playa Principal — Sayulita's main beach — is consistently clean. Across more than a year of monthly testing, every single Playa Principal sample has come back well below Mexican safe-swimming standards, usually by a factor of 5 to 50 times. If you're swimming, surfing, or letting kids splash in the main bay, the lab data is reassuring.
The North Side, near the river mouth, is variable. During the height of the rainy season (typically September through November), watershed runoff carries higher bacterial loads into that corner of the bay, and readings can exceed safe-swimming thresholds for a few weeks. By the start of the dry season the river-mouth area returns to acceptable levels and stays that way through spring and early summer.
Calling Sayulita "polluted" or its beach "dirty" as a blanket statement is not supported by the actual lab data. There are clearly defined locations and seasonal windows when one specific corner of the bay shows elevated readings, and there are many more weeks of the year when both beaches are pristine. Pro Sayulita's monthly testing program exists precisely so that residents, visitors, and businesses can make informed decisions rather than rely on rumor.
Independent monthly water testing is not free, and it is not done by the government. Pro Sayulita, a registered Mexican non-profit (A.C.), pays for every sample, every lab analysis, and every report you see on this page. They also fund beach cleanups, recycling, anti-litter campaigns, dog-sterilization clinics, and the day-to-day stewardship work that keeps Sayulita the place you love.
Pro Sayulita is funded purely by donations from homeowners, full-time residents, second-home owners, and local businesses — there is no government funding. If you live here, vacation here, own property here, or run a business here, please consider becoming a member or making a donation. Even a small annual contribution keeps the testing, cleanups, and community programs running.
Yes — based on the most recent independent lab testing, Playa Principal (the main Sayulita beach) is consistently safe for swimming, with bacterial readings well below Mexican federal recreational-water limits. The North Side near the river mouth is also typically safe outside of the late-rainy-season window of October–November, when runoff temporarily elevates readings.
Independent monthly testing shows Sayulita's main beach is not polluted under Mexican recreational-water standards. The river-mouth corner of the bay (the North Side) sees seasonal spikes during heavy rains, but the bulk of the bay tests within clean limits year-round.
December through July, during Sayulita's dry season, both beaches consistently test in the "excellent" range. The only window with occasional elevated readings is late September through November at the North Side sampling point.
Playa Principal — the main Sayulita beach in the center and south end of town — has the cleanest and most consistent water quality readings, regardless of season. The further you walk from the river mouth toward the south end of the bay, the better the historical data looks.
Water samples are collected and analyzed by an independent, certified Mexican water-quality laboratory. The testing program is funded entirely by Pro Sayulita, the local non-profit, with no government money involved.
NMP stands for "Número Más Probable" — Most Probable Number — the standard statistical method for estimating fecal coliform bacteria in a 100-milliliter water sample. Mexican guidelines treat anything below 200 NMP/100ml as safe for direct contact and recreation.
Data source: Pro Sayulita monthly water-quality testing program. Last updated April 25, 2026 with results from samples taken April 16, 2026. This page is updated each month as new test results become available.
