La Fortuna in August (2026): Green Season Weather, Crowds & What to Expect

⭐ Best August window: the last two weeks. Once the early-August holiday travel around the August 2 pilgrimage settles and northern school holidays start winding down, you get the same lush rainforest and powerful waterfalls with fewer people and easier tour availability.

💰 Average August hotel prices (La Fortuna town, mid-range):
Whole month: ~$110–160/night
Rough mid-range estimates; rates vary by property and booking lead time.

August is, in our view, the most honest month in La Fortuna. Nothing about it pretends to be dry season, and once you accept that, it delivers a version of the region that the January crowd never sees: rainforest so saturated it almost glows, the waterfall at genuinely intimidating volume, rivers running high enough to make rafting worth the trip, and a soundtrack of frogs and cicadas after dark. Compared with July it is marginally drier and, in our experience, a little more predictable in its rhythm.

We'd book August if you are travelling with school-age children and summer is your only window, or if the rainforest itself, rather than the volcano cone, is what you came for. The tradeoff is visibility. Arenal is frequently hidden, trails are muddy, and afternoons are often written off by rain. Our La Fortuna Waterfall guide and hot springs guide cover the two experiences that green season serves best of all.

Temperature and Humidity

Temperature is the least interesting thing about August, and that is genuinely useful to know. Days run around 30°C (86°F) and nights settle near 21°C (71°F), almost identical to every other month of the year. What changes is humidity, which is high enough that the heat feels heavier than the thermometer suggests and clothes take a long time to dry. Pack quick-dry fabrics and more shirts than you think you need. UV stays very high even under cloud, so sunscreen is not optional.

Rain Pattern

August averages around 300mm of rain, slightly less than July's 345mm and noticeably less than September and October. The shape of the day matters more than the total. What typically happens is a bright or lightly overcast morning, cloud building through late morning, and then heavy rain arriving somewhere between one and four in the afternoon, often falling hard for an hour or two before easing into evening drizzle. Some days stay clear all afternoon; some days rain from breakfast onward. The average day, though, gives you a usable morning.

Volcano Visibility and Trail Conditions

Arenal makes its own weather, and in green season it makes a lot of it. Expect fair rather than good visibility: the cone shows itself on some mornings, hides entirely on others, and is usually capped by the middle of the day. Sunrise is by far your best window, with a second, less reliable chance around sunset. On the ground, everything is wet. The waterfall staircase is slick, lava-field trails hold puddles, and ATV and horseback routes are properly muddy. None of this is dangerous with decent footwear, but it does slow you down and it does mean waterproof boots or shoes with real grip are worth packing.

August is the strange month where green-season weather meets summer-holiday demand. It is not busy in the January sense, but it is far from empty.

• August 1 to 10: the Virgen de los Ángeles pilgrimage on August 2 drives significant domestic travel, mostly toward Cartago rather than La Fortuna, but it fills roads and hotels nationally and the first week feels noticeably livelier.
• August 11 to 20: steady moderate demand from North American and European families still on school holidays, with Mother's Day on August 15 adding a domestic weekend bump.
• August 21 to 31: the quietest stretch of the month as northern school terms restart. Tour availability opens up and the town starts easing into September's low season.

Mid-range hotels sit around $110 to $160 a night, roughly the same as July and comfortably below dry-season rates, but still above the $90 to $130 floor that September and October bring. Most guests find that booking a day or two ahead is enough for all but the largest combination tours. Our take: if your dates have any flex at all, pushing into the last week of August buys you slightly fewer people at the waterfall for no meaningful change in weather.

If the volcano cone is the whole reason for your trip, August is not the month for it, and no amount of planning fixes that. If the rainforest is the point, August is genuinely one of the best months of the year. Our July guide and September guide lay out the months either side.

Being straight about this saves disappointment: August gives you fair volcano visibility, not good. Arenal's cone generates its own cloud, and in a month with 300mm of rain that cloud sits on the summit for a large share of daylight hours. Some visitors get a flawless clear morning; others spend four days in La Fortuna and never see the top of the mountain at all. Both outcomes are normal in August.

The pattern still works in your favour if you use it. Skies are clearest from first light to mid-morning, before daytime heating drives the cloud cap up, and there is often a brief second window near sunset when the afternoon storm has passed. In our view the only reliable strategy is repetition: look at the mountain every single morning you are here, and be ready to change your plan on the spot if the cone is out. One clear hour is worth reshuffling a day for.

The best vantage points remain Mirador El Silencio and the 1968 lava-flow trails on the western flank, plus the open sections of the hanging bridges circuits. Even fully clouded, the volcano hike is worth doing for the lava-field geology and the rainforest around it. Do note that Arenal has been in a resting phase since 2010, so there is no visible lava at night in any month. Our Arenal Volcano hike guide compares the trails and viewpoints in detail.

Around 300mm across the month, which sounds alarming written down and behaves more reasonably in practice. That figure puts August below July at 345mm, below September at 330mm, and well below October's 375mm peak, while sitting far above the 70 to 75mm of March and April. La Fortuna's position on the Caribbean slope means trade winds push moisture against the mountains all year, and in green season that moisture has nowhere to go but down.

The biggest difference between August and a dry-season month is not that it rains, it is how long and how hard. Instead of January's brief showers, August rain often falls as a genuine downpour that shuts down outdoor plans for a couple of hours. It also usually stops. Rivers rise fast and the waterfall roars, trails turn to mud, and then the sun comes back out over a landscape that looks freshly washed. Tours very rarely cancel outright; ziplines and canyoning may pause for lightning, and rafting actively benefits.

Two practical consequences. First, treat mornings as your only guaranteed working hours and book everything visibility-dependent before noon. Second, pack for wet: a real rain jacket rather than a windbreaker, shoes with grip, a dry bag for phone and camera, and a change of socks. We think the tradeoff is a fair one, since the same rain is what makes the waterfall and the forest so much better than in the dry months.

The single most useful thing to understand about La Fortuna's climate is that temperature barely moves all year, while rainfall swings roughly fivefold. Daytime highs sit between 29 and 32°C every month and nights hover around 21°C, so you pack the same clothes in January as in July. What actually changes your trip is how much rain falls, and when.

Full Month-by-Month Figures

What the Numbers Actually Mean

Three things stand out. First, March and April are the driest months by a wide margin, at roughly 70 to 75mm, which is why the dry season peaks then rather than in December. Second, October is the wettest at around 375mm, five times March, with September close behind. Third, the shoulder months do most of the work for value travelers: May and November sit between the extremes, offering greener rainforest and lower prices without the full weight of the wet season.

The temperature column is almost a flat line, and that is the point. Most people don't realize that choosing when to visit La Fortuna is a decision about rain and cloud, not about heat. If you want the volcano visible and the trails firm, come in the dry season. If you want thundering waterfalls, fuller rivers, and lower rates, the green season delivers, and you accept afternoon rain as the price.

ℹ️ Figures are rounded monthly averages from a single climate dataset and are indicative rather than exact. Published figures for La Fortuna vary noticeably between sources and weather stations, particularly for rainfall totals and rain-day counts, because the town sits on the Caribbean slope where conditions shift over short distances. Treat these as the shape of the year rather than a forecast.

Beyond the headline tours, August's saturated rainforest and warm rain open up a different set of smaller things to do:

• Free hot springs at the Tabacón river bridge, where thermal water runs under the road. Warm water in warm rain is one of the better green-season experiences, though the rocks are slippery and the river rises fast after a storm.
• El Salto rope swing: the local river swimming hole runs high and fast in August, which is exhilarating for confident swimmers and worth skipping after heavy rain.
• Frog ponds and butterfly gardens, low-effort, largely covered wildlife stops that are ideal fillers for a wet afternoon and genuinely good this month.
• Birdwatching around the Peñas Blancas river valley, quieter than dry season but still rewarding on a bright early morning.
• Lake Arenal viewpoints and the dam road, an easy self-drive that gives you shelter when the weather turns.
• La Fortuna central park and church, a pleasant evening stroll between showers, with the town at its liveliest during summer holidays.
• Chocolate and cacao demonstrations, almost entirely undercover and a good backup plan when an outdoor tour gets rained off.

August carries two significant dates in the Costa Rican calendar, both of which affect travel more than they affect La Fortuna itself.

• Virgen de los Ángeles, August 2: the country's biggest religious observance, centred on the basilica in Cartago. Enormous numbers of Costa Ricans walk there on foot over the preceding days, which fills roads across the Central Valley and books out hotels nationally. La Fortuna is far from the route, but domestic travel around this date is heavy and the first days of August feel busier everywhere.
• Mother's Day, August 15: a public holiday and a genuinely important family occasion in Costa Rica. Expect busy restaurants, domestic weekend travel, and some businesses running shortened hours.
• Northern school holidays: not an event, but the reason August still feels moderately busy. Once school terms restart in late August, visitor numbers drop noticeably heading into September.

Neither holiday should change your La Fortuna plans, but if you are driving from San José around August 1 or 2, allow extra time and expect pilgrims walking along road shoulders.

• Book everything outdoors for the morning. Rain concentrates from early afternoon onward, so treat 7 AM to noon as your working window and leave the rest for hot springs, coffee and cooking.
• Pack a real rain jacket, not a windbreaker. August rain falls hard. A proper waterproof shell, a dry bag, and quick-dry clothing make the difference between a good day and a miserable one.
• Bring footwear with grip. The waterfall's roughly 500 steps are genuinely slippery this month, as are the lava trails and bridge decks.
• Do not build the trip around the volcano. Views are fair at best in August. Treat a clear cone as a bonus and plan around rainforest, water, and wildlife instead.
• Say yes to rafting. High water makes August one of the best rafting months of the year, and it is one activity where the rain is an outright advantage.
• Use the afternoon deliberately. Hot springs in warm rain, a coffee farm under cover, or a cooking class all turn a wet afternoon from a loss into a highlight.
• Watch the early-August travel dates. The August 2 pilgrimage and the August 15 holiday drive heavy domestic movement; book road transfers and restaurants ahead around both.
• Expect insects and pack repellent. Warm, wet and lush also means mosquitoes, particularly at dusk and on night walks.
• Consider the last week. Late August is quieter as school terms restart, with the same weather and slightly better availability.
• Visiting at a different time of year? Our La Fortuna in July guide covers the veranillo dry spell that makes July a little more variable, and our La Fortuna in September guide covers the wettest, cheapest, emptiest stretch of the year.