In Costa Rica, the month of May marks the transition between the dry season and the rainy season. The shift in climate is generally gradual, and the arrival of the first rains offer a welcome respite from the hot and dry days of March and April.
The rainy season also promises cooler weather. Towards the beginning of May, temperatures along the Pacific can resemble those of previous months and hover in the 90s. As the days progress, however, daily highs slide into the comfortable 80s.
This country-wide average of 80 degrees Fahrenheit has made Costa Rica’s climate famous.
Life in the tropics
Due to the country’s geographical diversity, the rains usually start earlier in some areas and later in others. Atlantic and Pacific Ocean climate variations, such as El Niño and La Niña or other geographical climate patterns, can dramatically alter the average yearly forecast.
Last 2018, for example, experienced significantly higher rainfall during the rainy season than usual. Flooding and landslides affected some communities during the wetter months of September and October.
Costa Ricans are used to heavy rains and the tropical climate, however. Moreso, the Government of Costa Rica is prepared for dramatic weather fluctuations. The National Meteorological Institute (INM) is well versed in predicting incoming weather systems and advises the country’s inhabitants and visitors whenever needed.
Green Season Rates = Savings
May also marks the transition from high season rates to “green season” rates where everything from hotel rooms to adventure tours and rental cars are offered at a lower cost. There’s also an increased availability in hotel rooms and short-term property rentals making May an even better time to visit.
Many visitors take advantage of visiting in May for the mild weather conditions as well as to beat the crowds associated with summer vacations (June, July, and August).
North Pacific and Guanacaste
The North Pacific and Guanacaste regions of Costa Rica are drier on average.
Usually, once May rolls around the area’s inhabitants are desperate for the cool respite of afternoon rain showers. Daily rainfall usually occurs in the late afternoon and only lasts for a couple of hours.
September and October are the exceptions with occasional heavy rains lasting for days.
During the rainy months, the temperature rarely rises above the high 80s F. With nightly temperatures hovering in the 70s F.
Wherever you visit in Costa Rica the morning hours are usually the sunniest and best time to explore the outdoors. Overall humidity does rise during the green season; however, the northern quadrant remains drier on average than the rest of the country.
Central and South Pacific Coast
Weather along the Central and South Pacific Coast tends to be wetter than up north. This applies especially to the southern zone of the Osa Peninsula and interior mountains where rainforest covers much of the territory.
May is still a good time to visit before the heavier precipitation sets in. Wildlife tends to be more active as the environment thrives with the added moisture and “springtime” behavior affects certain species. Temperatures range between 71 and 90 F depending on the altitude and time of day.
Central Valley and Interior Mountains
The climate in the Central Valley and surrounding mountains reflects the same increase in daily rains and cooler temperatures. For most Costa Ricans, this period represents the start of the “winter months” and an end to the festivities and extended vacations of summer and the Easter holiday.
Average daily temperatures range between 62 and 78 F. Cool evenings often require a light jacket and slacks for those visiting the Capital San José or higher altitudes.
On the Caribbean Coast, the light rains and temperate weather that characterizes January through March are also coming to a close. The average daily rainfall is beginning to rise until September and October, which are considered the driest and most beautiful months to visit Costa Rica’s Atlantic side.
The mornings in this region are still stunningly beautiful and sunny in May, and the tropical environment is in full bloom. Temperatures range between 71 and 87 F with high humidity.