An unusual climate scenario in the middle of the rainy season

The months of July and August could present an unusual rainfall pattern in several regions of the country. According to projections from the Instituto Meteorológico Nacional (IMN), the Pacific North could register up to 50% less rainfall, while the Central Valley may experience a reduction close to 40% compared to historical averages for this time of year.

This forecast comes during a period that traditionally corresponds to the heart of the rainy season, when frequent downpours and significant accumulations are expected across much of the national territory.

The role of the “veranillo” and regional atmospheric patterns

The IMN explains that this behavior is related to the phenomenon popularly known as the “veranillo de San Juan”, a temporary decrease in rainfall that usually occurs between July and August, especially marked in the Pacific North.

This phenomenon is influenced by variations in regional atmospheric circulation, the strengthening of the trade winds, and changes in the position of the Intertropical Convergence Zone (ITCZ), factors that modify cloud formation and the frequency of rainfall over the country.

Regions most affected and possible impacts

The areas most affected by this reduction in rainfall would be:

• Guanacaste and sectors of the Pacific North
• A large part of the Central Valley

This decrease can have direct effects on agriculture, the availability of water for human consumption, river flows, and the planning of productive activities that depend on the rainy season.

At the same time, other regions of the country, such as the Caribbean and the Northern Zone, could maintain rainfall patterns closer to normal due to their distinct climate dynamics.

Importance of monitoring and official information

In view of this scenario, the IMN recommends that the population, agricultural producers, and local authorities remain attentive to official bulletins and updates, as these projections may adjust as atmospheric conditions evolve in the coming weeks.

Planning based on official meteorological information makes it possible to anticipate potential impacts and make informed decisions in climate-sensitive sectors.

Official and informative sources

• Instituto Meteorológico Nacional (IMN) — Seasonal climate forecasts and explanation of the veranillo de San Juan.
• Comisión Nacional de Prevención de Riesgos y Atención de Emergencias (CNE) — Preventive recommendations regarding climate variations.
• Semanario Universidad — Informative article based on IMN data.