Costa Rica will see warm mornings and stormy afternoons this week as Caribbean moisture moves across our country and helps fuel early rainy-season weather from May 4 to 10. The Instituto Meteorológico Nacional forecasts partly cloudy mornings followed by afternoon downpours and thunderstorms across much of the country, especially in the Pacific, Central Valley, and mountain areas of the Caribbean and Northern Zone.
The IMN’s weekly outlook calls for a progressive increase in cloud cover and rainfall starting Thursday, with wetter conditions likely to continue into the start of next week. Monday is expected to begin partly cloudy across most of Costa Rica before thunderstorms develop during the afternoon.
The strongest activity is likely in the Central Pacific, South Pacific, western Central Valley, and mountain areas. Rain may continue into the early evening along parts of the Pacific coast. Temperatures will stay warm. San José is forecast to reach around 28°C, with a low near 19°C. Liberia could climb to 37°C, while Quepos is expected to reach 31°C, Limón 29°C, and the southern Pacific around Golfito 33°C.
Tuesday and Wednesday should follow a similar pattern. Mornings will bring warm, partly cloudy weather, while afternoons will turn unstable, producing scattered showers and thunderstorms across the Pacific, Central Valley, and inland mountain areas. Some Pacific coastal communities may see rain push into the early night. In the Caribbean and Northern Zone, a few morning showers are possible near the coast, with more rain later in the mountains.
Rainfall is expected to pick up noticeably on Thursday as atmospheric instability increases. The Pacific and Central Valley are likely to see heavier and more widespread afternoon storms, making mornings the best time for beach trips, hikes, errands, and tours.
From Friday through Sunday, the chance of storms rises further, especially in the San Jose Area and Guanacaste. The Pacific coast, Central Valley, and mountain areas of the Caribbean and Northern Zone are all expected to see regular afternoon and evening downpours.
The pattern is a reminder that Costa Rica is moving deeper into the green season. Sunny or partly cloudy mornings can quickly give way to heavy rain, lightning, and slick roads by mid-afternoon.
Those visiting us and not used to our roads, should use extra caution during downpours, particularly on mountain routes such as Cerro de la Muerte, the road to Monteverde, and the Braulio Carrillo highway between San José and Limón. Reduced visibility, fog, falling branches, and standing water can make travel slower than expected.
Those going to the beach and/or on a tour along the Pacific coast should plan outdoor activities early in the day, especially from Thursday onward. Surfers may still find good morning windows, but afternoon storms could quickly change conditions.
The broader May outlook still points to a somewhat irregular rainy season. The forecast for May 4 to 31 calls for conditions that are generally less rainy than normal for the month, even with scattered downpours that may become intense at times. The 2026 outlook noted rainfall deficits of about 20% for parts of the Pacific, Central Valley, and western Northern Zone between May and July, while the Caribbean and eastern Northern Zone were expected to remain closer to normal.
For more complete information visit our weather forecast page.
