Costa Rica: rainy season still on hold, intense heat returns
In the area of the Karen Mogensen Reserve and Montezuma, the rainy season had shown some early signals in recent weeks, but it has not yet started in a structured way. In fact, over the past few days, a return to more stable and very hot conditions has been observed.
Maximum temperatures are once again frequently exceeding 33–35°C, accompanied by very high UV index values, reaching 12–13. These are extreme levels, linked to the Sun’s position near the zenith at this time of year: solar rays strike almost perpendicularly, increasing radiation intensity.
From a meteorological perspective, the tropical Pacific is already very warm and ready to provide energy, but atmospheric circulation is not yet fully favorable: the Intertropical Convergence Zone (ITCZ) remains relatively to the south, and the upper atmosphere still shows signs of stability.
The result is a transition phase: hot and mostly sunny days, with the possibility of isolated showers or heat thunderstorms, especially in the afternoon, but without persistent rainfall organization.
On a broader scale, attention is also on ENSO: several analyses indicate a possible transition toward El Niño conditions in the coming months, which could affect the rainy season on the Pacific side, making it less regular.
Based on current model outputs and climatological analysis, the most likely onset of the rainy season in the Nicoya area and the Karen Mogensen Reserve is expected within the first 10 days of May, although typical variability means that additional warm phases alternating with isolated rainfall cannot be ruled out.
We will continue monitoring the situation using data from the meteoclimatic station and provide updates in the coming days.
