Costa Rica’s rainy season is expected to intensify this week, with the National Meteorological Institute (IMN) warning of heavy rainfall and thunderstorms across the country.

The 39th tropical wave of the season,  which typically runs from May through November, is forecast to bring strong showers and storms to much of the country on Tuesday.

The system was crossing the Caribbean Coast of Panama on Monday and is expected to generate widespread downpours and thunderstorms as it moves across Costa Rica throughout the day.

Although the disturbance is anticipated to pass within 24 hours, the IMN cautioned that lingering moisture could cause additional showers through Wednesday.


Meteorologists are also tracking the 40th tropical wave of the season, which has a 90% chance of developing into a tropical depression or storm later this week.

That system is forecast to produce heavy rain and gusty winds across Central America from Thursday through Saturday.

Experts said the storm’s intensity is being fueled by the Intertropical Convergence Zone (ITCZ),  a belt of low pressure near the equator that frequently spawns storm activity,  which currently stretches across Costa Rica from the Pacific Ocean to the Caribbean Sea.

Rainfall forecasts by region include:

• Central Mountain Range: from 50 to 100 millimeters, with the heaviest rainfall at higher elevations.

• Pacific Coast (Guanacaste, Puntarenas): 40 to 80 millimeters.

• Central Valley (San José, Alajuela, Heredia, Cartago): 30 to 60 millimeters.

• Caribbean Coast (Limón): 10 to 30 millimeters, with thunderstorms likely.

The Ministry of Public Works and Transportation (MOPT) has issued a precautionary notice for Route 32, the main highway between San José and Limón.

Officials warn that overnight closures are possible due to heavy rainfall and landslide risks. Drivers are urged to consider alternate routes, such as Route 10 through Turrialba Canton (Cartago) and on to Siquirres Canton  (Heredia), before rejoining Route 32 toward Limón. Traffic updates will be shared through MOPT’s official social media channels.

The National Emergency Commission (CNE) has issued a Green Alert, the first advisory level, urging local emergency committees to remain on standby for possible incidents in the provinces of San José, Cartago, Alajuela and Heredia.


The Pacific Coast, including Puntarenas and Guanacaste, remains under a Yellow Alert,  the second level on the emergency scale,  advising local emergency units to stay prepared for potential large-scale weather impacts.


No alerts have been declared for the Caribbean Coast (Limón Province).


As of Monday, no Orange or Red Alerts had been issued beyond those already in place.

Authorities are advising residents to take the following precautions:

• Avoid rivers, lakes, and other bodies of water during heavy rain.

• In mountain areas, watch for landslides and falling debris.

• Households and businesses in flood-prone zones should review evacuation plans.

• Drivers should beware of flooding, slick roads, and low visibility.

• Stay indoors during thunderstorms and avoid electronic devices.

• Watch for strong winds that could bring down trees or power lines.

• Call 911 to report flooding, landslides, or fallen trees.

IMN is a government agency responsible for issuing weather forecasts, hazardous weather warnings, and related services to protect the public and inform organizations.

CNE works in partnership with communities and emergency responders to strengthen the nation’s preparedness, response, and recovery from natural hazards.

MOPT is the government agency responsible for managing the country’s roads, ports, and airports, as well as overseeing public transportation policy.

A.M. Costa Rica encourages readers to share this weather advisory with family, friends, and neighbors.