May is when Costa Rica turns green and cheap in the same fortnight. The Pacific rains arrive – Guanacaste jumps from 25 mm in April to about 200 mm – the brown dry forest goes emerald within two weeks, and high-season prices collapse. Locals call it invierno, winter. Almost everyone else calls it the green season, and it is badly undersold.
The rain map
What the green season actually means
Not what most people picture. From May to about August the Pacific pattern is consistent and manageable:
- Mornings are usually clear and sunny. The rain is convective – it builds through the day.
- Afternoon downpours arrive from roughly 2pm, heavy and often spectacular, and typically last one to three hours.
- Evenings frequently clear again.
The practical consequence: do the outdoor things in the morning and treat the afternoon as a siesta, a hot spring, or a covered lodge. It is a rhythm rather than a washout. September and October are the exception, when rain can last all day.
Why May is a good month
Continue planning your Costa Rica trip
- Prices fall hard. Pacific lodges and hotels drop from high-season rates almost overnight at the start of May.
- The country is green. The transformation from April’s brown dry forest is dramatic and fast.
- Rivers fill, which brings the waterfalls back – La Fortuna, Nauyaca, Río Celeste – and starts the whitewater rafting season on the Pacuare and Sarapiquí.
- Surf season begins on the Pacific; the green-season swell is the reason Costa Rica’s surf towns are busiest now rather than in the dry months.
- Far fewer people at Manuel Antonio, Monteverde and Arenal.
- Quetzal nesting continues through May in the highland cloud forests.
What gets harder
- Unpaved roads and river crossings. Many routes – particularly on the Nicoya peninsula and towards Monteverde – become genuinely difficult. A 4WD stops being optional in places, and some fords become impassable after heavy rain.
- Volcano views. Arenal spends more of the day in cloud. Early morning is the best chance.
- Mosquitoes increase with standing water. Repellent matters more from May on.
- Humidity rises across the lowlands.
1 May
Labour Day is a national public holiday, falling on a Saturday in 2027. Banks and offices close; beaches are busy with domestic visitors over the weekend.
Prices and crowds
The single biggest price drop of the Costa Rican year happens at the start of May. Together with June, it is the best value-to-conditions window – the rains are moderate, the country is green, and the rates are green-season. See what a trip to Costa Rica costs.
What to pack
A light rain jacket and quick-drying clothes – an umbrella is nearly useless in a tropical downpour. Insect repellent. Sandals plus closed shoes with grip for muddy trails. A dry bag for electronics. Binoculars.
The May 2027 calendar
- Start of May – the green season begins on the Pacific; the sharpest price drop of the year.
- Saturday 1 May – Labour Day, a national public holiday.
- Through May – clear mornings, afternoon downpours; rivers and waterfalls refill.
- From May – Pacific surf season and whitewater rafting season begin.
- To May – leatherback turtle nesting ends on the Caribbean coast.
- Through May – quetzal nesting continues in the highland cloud forests.
Read alongside
- Costa Rica in April – the last dry month.
- Costa Rica in June – green season settled.
- Costa Rica in September – wettest Pacific, driest Caribbean.
- Best time to visit Costa Rica – all twelve months compared.
- Costa Rica in 10 days – how the regions connect.
- Costa Rica travel guide – coasts, volcanoes and cloud forest.
- Trip to Costa Rica cost – green-season numbers.
Frequently asked
Is the green season a bad time to visit Costa Rica?
No, and it is badly undersold. From May to August mornings are usually clear, the rain comes as heavy afternoon downpours lasting one to three hours, and evenings often clear again. Plan outdoor activities for the morning.
How much cheaper is May?
Substantially. Pacific lodges and hotels drop from high-season rates almost immediately at the start of May, which is the biggest single price change in the Costa Rican year.
Do I need a 4WD in May?
In places, yes. Unpaved roads and river fords on the Nicoya peninsula and towards Monteverde become difficult once the rains start, and some crossings are impassable after heavy rain.
Can you see Arenal volcano in May?
Less reliably than in the dry season – it spends more of the day in cloud. Early morning is the best chance.
Is May good for surfing in Costa Rica?
Yes. The Pacific surf season runs with the green season, which is why the surf towns are busiest now rather than in the dry months.
Does it rain all day in May?
Rarely. That pattern belongs to September and October. May rain is convective – it builds through the day and breaks in the afternoon.
Are there more mosquitoes in the green season?
Yes, standing water increases them from May onwards. Repellent matters more than in the dry months.
Is 1 May a holiday in Costa Rica?
Yes, Labour Day is a national public holiday. It falls on a Saturday in 2027, making a busy domestic beach weekend.
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Written by
John Morrison is the founder and lead travel writer at Packzup. Over the past decade he has explored destinations across Africa, the Americas, Asia, Europe, the Middle East, and Oceania — always self-funded, never on a press trip.
