Figuring out when to visit Chacahua is one of those decisions that can shape your entire experience. Visit during the wrong month for the wrong reasons and you might wonder what all the fuss was about. Visit during the right one and you will understand why people keep coming back to this remote stretch of the Oaxacan coast. Unlike resort towns where the weather barely matters because you spend half your time indoors, Chacahua is an outdoor destination — the season you choose determines what you see, what you spend, and how the place feels.
We have watched this coastline through every month of the year while building Montserrat Reserve, our eco retreat near the Chacahua lagoon. Here is what we have learned about each season, and how to pick the right time for the trip you actually want.
When to Visit Chacahua: Dry Season (November to May)
The dry season is the easier sell. Skies stay clear for days at a stretch, humidity drops to manageable levels, and the roads and trails that become muddy obstacles during the rains are firm and walkable. For most first-time visitors, this is the default recommendation — comfortable weather with the fewest logistical complications.
November and December
These are arguably the most balanced months to visit. The rainy season has just ended, so the landscape is still lush and green from months of downpour, but the afternoon storms have stopped. Temperatures hover between 24 and 32 degrees Celsius, with pleasantly cool evenings. Humidity is noticeably lower than the preceding months.
November marks the beginning of the migratory bird season, which makes the lagoon system come alive with species you will not see the rest of the year. Turtle nesting season is still active through December, so there is a good chance of witnessing a hatchling release on the beach at sunset. The bioluminescence in the lagoon remains strong through November before tapering off.
Tourist numbers start to climb in December, particularly around the holidays. Prices follow. If you can visit in the first two weeks of December before the holiday rush, you get the best of both worlds — dry weather, active wildlife, and moderate crowds.
January and February
This is peak season. The weather is at its most comfortable — warm days in the high 20s to low 30s Celsius, low humidity, and almost no rain. These are the months when Chacahua feels most conventionally pleasant, the kind of weather that makes you want to spend every waking hour outside.
The trade-off is that everyone else had the same idea. Peak season brings the highest prices for accommodation and boat transfers. The village is still far from crowded by any normal beach town standard — we are talking about a place with a few hundred residents and no paved roads — but you will share the beach with more visitors than during the off-season. Accommodation in the village can fill up, especially on weekends and around Mexican holidays.
Birding remains excellent through February. The migratory species are well established in the lagoon system, and early morning kayak trips through the mangroves are some of the most productive bird watching outings you can have on the entire Oaxacan coast.
March to May
The transition months. March is still dry and pleasant, though temperatures start climbing. By April, the heat becomes serious — daily highs can push past 35 degrees Celsius, and the humidity begins its slow ascent toward rainy season levels. May is hot, sticky, and the first scattered afternoon showers begin to appear toward the end of the month.
The upside of these months is economic and experiential. Prices drop as the peak season crowd disperses. You will find it easier to book accommodation on short notice, negotiate better rates for boat tours, and have long stretches of beach entirely to yourself. The surf starts picking up in April as southern hemisphere swells begin arriving, making this a sweet spot for surfers who want waves without the rain.
If you handle heat well and care more about solitude than perfect weather, late March or early April is an underrated window.
When to Visit Chacahua: Rainy Season (June to October)
The rainy season scares off a lot of visitors, and honestly, that is part of its appeal. Yes, it rains. But it does not rain the way people from temperate climates imagine. This is not days of gray drizzle. The typical pattern on the Oaxacan coast is hot, sunny mornings followed by dramatic afternoon thunderstorms that dump rain for one to three hours, after which the sky clears and the evening is calm and warm. You still get plenty of sun. You just also get spectacle.
June and July
The rains arrive in earnest in June. Afternoons bring heavy downpours, sometimes with thunder that rolls across the lagoon like a drum line. The landscape begins its transformation from the sun-bleached browns of late dry season to a deep, saturated green that looks almost artificial in photographs. Everything grows aggressively — the forest thickens, the lagoon swells, and the air smells like wet earth and flowers.
June marks the beginning of the bioluminescence peak season. The combination of warmer water temperatures, nutrient runoff from the rains, and longer nights creates conditions that make the lagoon glow with unusual intensity. If seeing the bioluminescence is your primary reason for visiting, June through November is your window, with the strongest displays often occurring between July and September on new moon nights.
Turtle nesting begins in July, with olive ridley sea turtles hauling themselves onto the beach at night to lay eggs. The hatchling releases — one of the most memorable experiences available on this coast — start roughly 45 to 60 days later, carrying through until December.
Tourist numbers drop significantly. You will likely have the beach to yourself most mornings, and boat tours feel more like private excursions. Prices for accommodation and services are at their lowest.
August and September
These are the wettest months. Rainfall is heaviest, humidity is highest, and temperatures remain in the high 20s to mid-30s Celsius even on cloudy days. The lagoon is at its fullest, and some of the lower trails and paths near the water can flood temporarily after heavy rains.
This is also the heart of the eastern Pacific hurricane season. Chacahua does not get hit by hurricanes frequently — the geography of the Oaxacan coast and the typical storm tracks offer some protection — but tropical storms and peripheral weather from distant hurricanes can bring extended periods of heavy rain, rough seas, and disrupted boat service. We cover hurricane considerations in more detail below.
For travelers who are flexible and comfortable with uncertainty, August and September offer the lowest prices of the year, the most intense bioluminescence, and a rawness to the landscape that the dry season simply cannot match. The surf is often at its best, with consistent south and southwest swells pushing through.
October
The rains begin tapering off in the second half of October. You get a transitional period where the landscape is still impossibly green but the afternoon storms become shorter and less frequent. Temperatures start cooling slightly, especially in the evenings.
October is a strong month for wildlife. Turtle nesting continues, the bioluminescence is still active, and the lagoon ecosystem is rich from months of rainfall. It is also one of the last months of reliable surf swells before the season winds down.
If you want the benefits of the rainy season — lower prices, fewer tourists, active wildlife, green landscape — without the heaviest rains, the second half of October is one of the best-kept timing secrets on this coast.
Month-by-Month Guide: When to Visit Chacahua
| Month | Avg Temp (C) | Rainfall | Crowds | Prices | Highlights |
|---|---|---|---|---|---|
| January | 24–32 | Very low | Peak | High | Birding, clear skies, comfortable weather |
| February | 24–33 | Very low | Peak | High | Birding, dry trails, best overall weather |
| March | 25–34 | Low | Moderate | Moderate | Heat building, crowds thinning, dry |
| April | 26–35 | Low | Low | Low–Moderate | Surf season starts, hot days, good value |
| May | 27–35 | Low–Moderate | Low | Low | Hot and humid, first rains at month end |
| June | 26–34 | Moderate–High | Low | Low | Rains begin, bioluminescence peak starts, lush green |
| July | 26–33 | High | Low | Low | Turtle nesting begins, strong bioluminescence, surf |
| August | 26–33 | Very high | Very low | Lowest | Wettest month, best bioluminescence, hurricane risk |
| September | 25–33 | Very high | Very low | Lowest | Heavy rain, great surf, highest hurricane risk |
| October | 25–33 | Moderate–High | Low | Low | Rains easing, turtles, bioluminescence, green landscape |
| November | 24–32 | Low | Moderate | Moderate | Dry season returns, migratory birds arrive, turtles |
| December | 24–31 | Very low | High | High | Holiday peak, cool evenings, bird watching |
Best Time for Specific Activities
Bioluminescence: June to November
The bioluminescent plankton in the Chacahua lagoon are present year-round, but the intensity varies dramatically by season. The strongest displays occur between June and November, when warmer water temperatures and nutrient-rich runoff from the rains create ideal conditions for dinoflagellate blooms. Within that window, July through September tends to produce the most spectacular shows.
Moon phase matters as much as month. Schedule your lagoon tour on or near a new moon for the darkest skies and the most vivid glow. Full moon nights wash out the bioluminescence almost entirely.
Surfing: April to October
Chacahua’s beach break picks up southern hemisphere swells that arrive between April and October, with the most consistent conditions from June through September. The waves are not enormous — this is not Puerto Escondido — but the swell is reliable, the lineup is uncrowded, and the water is warm enough that you do not need a wetsuit.
Morning sessions before 9 AM offer the cleanest conditions before afternoon onshore winds arrive. During the dry season, waves are smaller and less frequent, though occasional northwest swells in winter can produce fun days.
Bird Watching: November to March
The migratory season brings the greatest diversity of species to the lagoon system. Roseate spoonbills, wood storks, white ibis, and dozens of other migratory birds join the resident population of herons, egrets, kingfishers, and frigatebirds. Early morning kayak trips through the mangrove channels during these months are extraordinary.
Resident species are present year-round, so birding is never truly off-season here. But the November-to-March window is when the numbers and variety peak.
Turtle Nesting and Releases: July to December
Olive ridley sea turtles nest on the beaches near Chacahua from July through December. Hatchling releases begin roughly 45 to 60 days after nesting, with the highest frequency of releases occurring between September and December. These events are organized by local conservation groups, happen at sunset, and are free to attend.
If a turtle release is a priority for your trip, plan for late September through November for the best odds of witnessing one.
Hurricane Season Considerations
The eastern Pacific hurricane season runs from May 15 to November 30, with peak activity between August and October. Chacahua sits on a stretch of coast that is less frequently in the direct path of major hurricanes compared to the Caribbean or Gulf coasts, but tropical storms and the outer bands of passing hurricanes can still bring several consecutive days of heavy rain, high winds, and rough seas.
When tropical weather affects the area, boat service between Zapotalito and Chacahua can be suspended. This means you could be delayed getting in or out of the village. If you are visiting during peak hurricane months, build buffer days into your itinerary, monitor weather forecasts, and have a flexible attitude. Travel insurance that covers weather disruptions is worth the cost.
It is important to keep perspective. Most rainy season visits are not affected by hurricanes at all. The typical experience is sunny mornings, afternoon rain, and clear evenings. But the possibility exists, and planning for it is common sense.
What to Pack: Dry Season vs Rainy Season
Dry Season Essentials (November to May)
- Lightweight, breathable clothing (cotton and linen over synthetics)
- Sun protection: hat, reef-safe sunscreen, UV shirt
- Light layers for cooler evenings in December and January
- Insect repellent (mosquitoes are present year-round, though less aggressive in dry months)
- Sturdy sandals or water shoes for the boat and beach
- Cash in pesos — there are no ATMs in Chacahua
- Reusable water bottle
- Headlamp or flashlight for nighttime walks in the village
Rainy Season Essentials (June to October)
Everything from the dry season list, plus:
- Quick-dry clothing (you will get caught in a downpour at some point — embrace it)
- A light rain jacket or waterproof windbreaker
- Waterproof bag or dry sack for electronics and cash
- Extra insect repellent — mosquitoes are significantly more active during the rains
- Waterproof sandals with grip (trails get slippery)
- A thin long-sleeve layer for evenings when mosquitoes are worst
- Patience and a willingness to adjust your plans around afternoon storms
Regardless of season, pack light. You will carry your bags on and off boats, and there is no need for anything formal. Chacahua is a shorts-and-sandals destination twelve months a year.
So When Should You Actually Go?
There is no single best time to visit Chacahua. There is only the best time for what you want from the trip.
If you want comfortable weather, easy logistics, and the fewest surprises, visit between November and February. You will pay more and share the beach with more visitors, but the conditions are reliably pleasant.
If you want bioluminescence at its most intense, turtle releases on the beach, uncrowded surf, and prices at their lowest, visit between July and October. You will deal with rain and humidity, but you will also see the coast at its most alive.
If you want the best balance of value, weather, and wildlife, target November or the second half of October. The rains have eased, the dry season tourists have not yet arrived, prices are reasonable, and the bioluminescence and turtles are still active.
Whatever month you choose, Chacahua rewards travelers who come with flexibility and few expectations. This is not a place that performs on a schedule. It reveals itself on its own terms — and that, more than any weather forecast, is what makes it worth the trip.
For a closer look at the region and how to get here, visit our location page. And if you are looking for a place to stay that is built around the rhythms of this coast — designed for slow, intentional time in nature — Montserrat Reserve is an eco retreat set within the coastal forest near the Chacahua lagoon, with natural pools, organic gardens, and independent villas that let you experience both seasons in comfort.