Weather Warning (Update)

Greater occurrence of rainfall in the Pacific

June 12, 2025

5:00 p.m.

Diagnostic: The Intertropical Convergence Zone is beginning to strengthen off the Pacific coast of Costa Rica, increasing the flow of moisture from the ocean to both sides of the country.

During the afternoon, moderate to heavy rain and downpours were recorded in several parts of the country. Among the most significant accumulations are:

• Central Valley, between 1 and 10 mm.
• North Pacific, between 20 and 50 mm, with maximum rainfall in the vicinity of Cañas and Hojancha.
• North Zone, between 10 and 32 mm, with the maximum rainfall in Los Chiles.
• Central and South Pacific, between 20 and 45 mm, with maximum rainfall in Cerro Buenavista and Río Nuevo de Pérez Zeledón.
• Caribbean, amounts below 10 mm.

Forecast: Rain will continue throughout the afternoon and evening in the North, Central, and South Pacific, with the possibility of thunderstorms, especially in the late afternoon and early evening. Accumulations of between 15 and 50 mm are estimated, with peak rainfall of between 60 and 100 mm over periods of 6 to 12 hours.

In the Central Valley, scattered light to moderate rainfall is expected, with accumulations of between 10 and 20 mm, with peak rainfall of up to 40 mm.

In the Northern Zone and the Caribbean Mountains, isolated but intense downpours are expected, with amounts between 10 and 40 mm, and possibly higher localized amounts. Scattered showers will occur in the lower reaches of these regions.

There is a high possibility of continued rainfall during the early morning hours, especially in the North Pacific and the Central and South Pacific coasts. The possibility of light rain and fog banks cannot be ruled out in the Greater Metropolitan Area.

⚠ Note: Analyses and numerical models continue to indicate an increase in rainfall for at least the next 2-3 days (with the possibility of further extension), especially on the Pacific side. This is due to the strengthening of the Intertropical Convergence Zone, the passage of OT#5 this Friday, and the possible formation of a low-pressure system in the Pacific near the country this weekend. The IMN will continue to monitor these systems and provide a forecast update when appropriate.

Warning: Pay special attention to the Nicoya Peninsula, the Sarapiquí Basin, and the South Pacific, as these areas have very high soil saturation levels between 85-95%, which increases the vulnerability to the risk of incidents.

Due to the above, the IMN recommends:

• Caution due to sewer saturation in areas prone to this type of flooding.
• Prepare for thunderstorms and seek shelter in a safe place if strong wind gusts occur or are perceived near storm clouds, due to the possible fall of tree branches, power lines, etc. These gusts can reach 80 km/h in some isolated cases.
• Stay informed through social media: Twitter: @IMNCR, Facebook: Instituto Meteorológico Nacional CR, and the website: www.imn.ac.cr

Paulo J. Solano S.
Meteorologist
DMSA-IMN