Subseasonal forecast

Valid from  jun 30-jul 27 , 2025

(4 weeks)

General comment:

Starting July 7, the Canícula period will begin, significantly reducing rainfall amounts as a result of decreased atmospheric moisture content. These dry conditions will persist throughout July. Temperatures are expected to remain within normal ranges over the country in the coming weeks.
Pronóstico Estacional

Fig. 1. Weekly precipitation forecast by region for the next 4 weeks.

 

1.  Forecast for July 7–13, 2025

 

Rainy conditions are expected in the Caribbean region, as a result of an increase in trade winds. Below-normal rainfall is forecast for the Pacific and Northwestern Northern Zone (amounts less than 50 mm in the Pacific and Central Valley). The Canícula dry period will begin this week in the Pacific and Northwestern Northern Zone.
(Expected totals: Pacific 10–50 mm/week, Caribbean–Northern Zone 10–60 mm, Central Valley 5–30 mm.)

  • Probability of extreme events: low (around 10%)

  • Forecast uncertainty: low

2.  Forecast for July 14–20, 2025

 

Rainy conditions will continue in the Caribbean, as a result of increased trade winds. Normal conditions are expected in the Central Valley, South Pacific, and Northeastern Northern Zone, while much drier-than-normal conditions will persist in the Pacific and Northwestern Northern Zone. The Canícula will intensify, especially in the North Pacific, where rainfall will be much lower than normal.

  • Probability of extreme events: low (around 10%)

  • Forecast uncertainty: low

3. Forecast for July 21–27, 2025

 

Rainy conditions will continue in the Southern Caribbean due to stronger trade winds, with below-normal rainfall expected in the North Pacific and Northern Zone. The rest of the country will experience normal conditions.

  • Probability of extreme events: low (around 10%)

  • Forecast uncertainty: moderate

4.  Forecast for July 28–August 3, 2025

 

Normal conditions are expected across much of the country this week, with below-normal rainfall in the North Pacific.

  • Probability of extreme events: low (around 10%)

  • Forecast uncertainty: high

Potential Extreme Event Forecast (July 7–13, 2025)

 

No extreme precipitation events or nearby tropical cyclones are expected in the Costa Rica region during this period.


Fig. 2. Forecast of extreme events for the next 2 weeks (training areas).


 

 

Forecaster: Daniel Poleo
Maps: Nury Sanabria Valverde
Unidad de aplicaciones climáticas
Departamento de Desarrollo/IMN