Most Costa Rica weather advice describes one country with two seasons. The country has at least three weather regions and they do not agree with each other, which is why a trip planned on a single calendar so often meets rain it did not expect.
The three calendars
The Pacific north. Guanacaste, 86.9 nautical miles from San José, is the driest part of the country. December to April is genuinely dry — brown hills, hard sun. September and October are the wettest.
The Pacific south and centre. Manuel Antonio at 33.4 nautical miles and Drake Bay at 83.5 are greener and wetter year-round. The dry season is real here but shorter and less absolute.
The Caribbean. Runs on its own calendar entirely. September and October — the wettest months on the Pacific — are often the best months on the Caribbean side. That inversion catches most first-time visitors.
And the mountains do what mountains do: cooler, cloudier, and wetter than the lowlands below them, whatever the month.
Month by month, roughly
December to February. Dry and busy. The most reliable weather and the highest prices.
March and April. Hot and still dry. Guanacaste is at its most parched; the south stays green.
May and June. The rains begin, usually as afternoon storms with clear mornings. Green, quiet, and good value.
July and August. A partial break in the rains on the Pacific — locally called the little summer — and a reliable wet stretch on the Caribbean.
September and October. The wettest months on the Pacific and the driest on the Caribbean. Some Pacific lodges close.
November. The transition. Early November can still be wet; late November is often excellent and much quieter than December.
What the rain actually looks like
Not all day. Through most of the wet season it is a clear morning and a storm after lunch.
That pattern is the single most useful planning fact in this article: schedule the outdoors and the moving in the morning, and leave afternoons soft. A green-season trip planned that way barely notices the rain.
Which months are genuinely difficult
Late September and October on the Pacific. Not because of the rain volume but because the rain can persist through the morning, which is when the pattern above breaks down.
And any month in the mountains if you needed a view. Cloud forest is called that for a reason.
What this means for flying
We fly year-round. In the rainy season the pilot in command decides; if weather stops a flight, it is rescheduled at no cost. Visual airfields close on ceiling rather than rainfall, which is why a day that looks wet can be perfectly flyable and a grey one can be closed.
The practical consequence for your plan: in the wet months, earlier departures do better, and it is worth keeping the day you fly free of anything that cannot move. We show a "from" price per route; the final fare depends on the date, the group and the baggage, and is confirmed in writing before booking.
Choosing by what you want
Reliable sun: January to March, Guanacaste. Green, quiet, cheaper: May, June, November. Wildlife: the wet months, when everything is active and breeding. Surf: depends entirely on the coast and the swell, not the season. Caribbean: September and October, against every instinct.
Frequently asked
Does Costa Rica have one dry season?
No. The dry season is a Pacific idea. The Caribbean runs on its own calendar and the mountains on another.
When is the Caribbean best?
Often September and October — the wettest months on the Pacific side.
What does wet-season rain actually look like?
Usually a clear morning and an afternoon storm, not all-day rain.
How should I plan around it?
Put the outdoors and the moving in the morning and leave afternoons soft.
Which months are genuinely hard?
Late September and October on the Pacific, when rain can persist through the morning.
Why does a wet day sometimes fly fine?
Because visual airfields close on cloud base rather than rainfall. Grey can be worse than wet.
Plan it with us
We fly year-round. In the rainy season the pilot in command decides; if weather stops a flight, it is rescheduled at no cost.